Table of Contents
Starting a free software project is a twofold task. The software needs to acquire users, and to acquire developers. These two needs are not necessarily in conflict, but the interaction between them adds some complexity to a project's initial presentation. Some information is useful for both audiences, some is useful only for one or the other. Both kinds of information should subscribe to the principle of scaled presentation: the degree of detail presented at each stage should correspond to the amount of time and effort put in by the reader at that stage. More effort should always result in more reward. When effort and reward do not correlate reliably, most people will lose faith and stop investing effort.
The corollary to this is that appearances matter. Programmers, in particular, often don't like to believe this. Their love of substance over form is almost a point of professional pride. It's no accident that so many programmers exhibit an antipathy for marketing and public relations work, nor that professional graphic designers are often horrified at the designs programmers come up with on their own.
This is a pity, because there are situations where form is substance, and project presentation is one of them. For example, the very first thing a visitor learns about a project is what its home page looks like. This information is absorbed before any of the actual content on the site is comprehended — before any of the text has been read or links clicked on. However unjust it may be, people cannot stop themselves from forming an immediate first impression. The site's appearance signals whether care was taken in organizing the project's presentation. Humans have extremely sensitive antennae for detecting the investment of care. Most of us can tell in one glance whether a home page was thrown together quickly or was given serious thought. This is the first piece of information your project puts out, and the impression it creates will carry over to the rest of the project by association.
Thus, while much of this chapter talks about the content your project should start out with, remember that its look and feel matter too. Because the project web site has to work for two different types of visitors — users and developers — special attention must be paid to clarity and directedness. Although this is not the place for a general treatise on web design, one principle is important enough to deserve mention, particularly when the site serves multiple (if overlapping) audiences: people should have a rough idea where a link goes before clicking on it. For example, it should be obvious from looking at the links to user documentation that they lead to user documentation, and not to, say, developer documentation. Running a project is partly about supplying information, but it's also about supplying comfort. The mere presence of certain standard offerings, in expected places, reassures users and developers who are deciding whether they want to get involved. It says that this project has its act together, has anticipated the questions people will ask, and has made an effort to answer them in a way that requires minimal exertion on the part of the asker. By giving off this aura of preparedness, the project sends out a message: "Your time will not be wasted if you get involved," which is exactly what people need to hear.
If you use a "canned hosting" site (see the section called “Canned Hosting”), one advantage of that choice is that those sites have a default layout that is similar from project to project and is pretty well-suited to presenting a project to the world. That layout can be customized, within certain boundaries, but the default design prompts you to include the information visitors are most likely to be looking for.
Before starting an open source project, there is one important caveat:
Always look around to see if there's an existing project that does what you want. The chances are pretty good that whatever problem you want solved now, someone else wanted solved before you. If they did solve it, and released their code under a free license, then there's no reason for you to reinvent the wheel today. There are exceptions, of course: if you want to start a project as an educational experience, pre-existing code won't help; or maybe the project you have in mind is so specialized that you know there is zero chance anyone else has done it. But generally, there's no point not looking, and the payoff can be huge. If the usual Internet search engines don't turn up anything, try searching directly on https://github.com/, https://freshcode.club/, https://openhub.net/, and in the Free Software Foundation's directory of free software at https://directory.fsf.org/.
Even if you don't find exactly what you were looking for, you might find something so close that it makes more sense to join that project and add functionality than to start from scratch yourself. See the section called “Evaluating Open Source Projects” for a discussion of how to evaluate an existing open source project quickly.
You've looked around, found that nothing out there really fits your needs, and decided to start a new project.
The hardest part about launching a free software project is transforming a private vision into a public one. You or your organization may know perfectly well what you want, but expressing that goal comprehensibly to the world is a fair amount of work. It is essential, however, that you take the time to do it. You and the other founders must decide what the project is really about — that is, decide its limitations, what it won't do as well as what it will — and write up a mission statement. This part is usually not too hard, though it can sometimes reveal unspoken assumptions and even disagreements about the nature of the project, which is fine: better to resolve those now than later. The next step is to package up the project for public consumption, and this is, basically, pure drudgery.
What makes it so laborious is that it consists mainly of
organizing and documenting things everyone already
knows — "everyone", that is, who's been involved in the project so
far. Thus, for the people doing the work, there is no immediate
benefit. They do not need a
README file giving
an overview of the project, nor a design document.
They do not need a carefully arranged code tree conforming to the
informal but widespread standards of software source distributions.
Whatever way the source code is arranged is fine for them, because
they're already accustomed to it anyway, and if the code runs at all,
they know how to use it. It doesn't even matter, for them, if the
fundamental architectural assumptions of the project remain
undocumented; they're already familiar with that too.
Newcomers, on the other hand, need all these things. Fortunately, they don't need them all at once. It's not necessary for you to provide every possible resource before taking a project public. In a perfect world, perhaps, every new open source project would start out life with a thorough design document, a complete user manual (with special markings for features planned but not yet implemented), beautifully and portably packaged code, capable of running on any computing platform, and so on. In reality, taking care of all these loose ends would be prohibitively time-consuming, and anyway, it's work that one can reasonably hope others will help with once the project is under way.
What is necessary, however, is that enough investment be put into presentation that newcomers can get past the initial obstacle of unfamiliarity. Think of it as the first step in a bootstrapping process, to bring the project to a kind of minimum activation energy. I've heard this threshold called the hacktivation energy: the amount of energy a newcomer must put in before she starts getting something back. The lower a project's hacktivation energy, the better. Your first task is bring the hacktivation energy down to a level that encourages people to get involved.
Each of the following subsections describes one important aspect of starting a new project. They are presented roughly in the order that a new visitor would encounter them, though of course the order in which you actually implement them might be different. You can treat them as a checklist. When starting a project, just go down the list and make sure you've got each item covered, or at least that you're comfortable with the potential consequences if you've left one out.
Put yourself in the shoes of someone who's just heard about your project, perhaps by having stumbled across it while searching for software to solve some problem. The first thing they'll encounter is the project's name.
A good name will not automatically make your project successful, and a bad name will not doom it — well, a really bad name probably could do that, but we start from the assumption that no one here is actively trying to make their project fail. However, a bad name can slow down adoption of the project, either because people don't take it seriously, or because they simply have trouble remembering it.
A good name:
Gives some idea what the project does, or at least is related in an obvious way, such that if one knows the name and knows what the project does, the name will come quickly to mind thereafter.
Is easy to remember. Here, there is no getting around the fact that English has become the default language of the Internet: "easy to remember" usually means "easy for someone who can read English to remember." Names that are puns dependent on native-speaker pronounciation, for example, will be opaque to the many non-native English readers out there. If the pun is particularly compelling and memorable, it may still be worth it; just keep in mind that many people seeing the name will not hear it in their head the way a native speaker would.
Is not the same as some other project's name, and does not infringe on any trademarks. This is just good manners, as well as good legal sense. You don't want to create identity confusion. It's hard enough to keep track of everything that's available on the Net already, without different things having the same name.
The resources mentioned earlier in the section called “But First, Look Around” are useful in discovering whether another project already has the name you're thinking of. For the U.S., trademark searches are available at http://www.uspto.gov/.
If possible, is available as a domain name in the
.org top-level domains. You
should pick one, probably
to advertise as the official home site for the project;
the other two should forward there and are simply to
prevent third parties from creating identity confusion
around the project's name. Even if you intend to host the
project at some other site (see
the section called “Hosting”), you
can still register project-specific domains and forward
them to the hosting site. It helps users a lot to have a
simple URL to remember.
If possible, is available as a username on https://twitter.com/ and other microblog sites. See the section called “Own the Name in the Important Namespaces” for more on this and its relationship to the domain name.
For large projects, it is a good idea to own the project's name in as many of the relevant namespaces on the Internet as you can. By namespaces, I mean not just the domain name system, but also online services in which account names (usernames) are the publicly visible handle by which people refer to the project. If you have the same name in all the places where people would look for you, you make it easier for people to sustain a mild interest in the project until they're ready to become more involved.
For example, the Gnome free desktop project has the https://gnome.org/ domain
name, the https://twitter.com/gnome Twitter handle, the https://identi.ca/gnome username at
Identi.ca, the https://github.com/gnome username at
GitHub.com, and on the freenode IRC
network (see the section called “IRC / Real-Time Chat Systems”) they have the channel
#gnome, although they also maintain their own IRC servers
(where they control the channel namespace anyway, of course).
All this makes the Gnome project splendidly easy to find: it's usually right where a potential contributor would expect it to be. Of course, Gnome is a large and complex project with thousands of contributors and many subdivisions; the advantage to Gnome of being easy to find is greater than it would be for a newer project, since by now there are so many ways to get involved in Gnome. But it will certainly never harm your project to own its name in as many of the relevant namespaces as it can, and it can sometimes help. So when you start a project, think about what its online handle should be and register that handle with the online services you think you're likely to care about. The ones mentioned above are probably a good initial list, but you may know others that are relevant for the particular subject area of your project.
Once they've found the project's home site, the next thing people will look for is a quick description or mission statement, so they can decide (within 30 seconds) whether or not they're interested in learning more. This should be prominently placed on the front page, preferably right under the project's name.
The description should be concrete, limiting, and above all, short. Here's an example of a good one, from https://hadoop.apache.org/:
The Apache™ Hadoop® project develops open-source software for reliable, scalable, distributed computing.
The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-availability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-available service on top of a cluster of computers, each of which may be prone to failures.
In just four sentences, they've hit all the high points, largely by drawing on the reader's prior knowledge. That's an important point: it's okay to assume a minimally informed reader with a baseline level of preparedness. A reader who doesn't know what "clusters" and "high-availability" mean in this context probably can't make much use of Hadoop anyway, so there's no point writing for a reader who knows any less than that. The phrase "designed to detect and handle failures at the application layer" will stand out to engineers who have experience with large-scale computing clusters — when they see those words, they'll know that the people behind Hadoop understand that world, and the first-time visitor will thus be likely to give Hadoop further consideration.
Those who remain interested after reading the mission statement will next want to see more details, perhaps some user or developer documentation, and eventually will want to download something. But before any of that, they'll need to be sure it's open source.
The front page must make it unambiguously clear that the project is open source. This may seem obvious, but you would be surprised how many projects forget to do it. I have seen free software project web sites where the front page not only did not say which particular free license the software was distributed under, but did not even state outright that the software was free at all. Sometimes the crucial bit of information was relegated to the Downloads page, or the Developers page, or some other place that required one more mouse click to get to. In extreme cases, the license was not given anywhere on the web site at all — the only way to find it was to download the software and look at a license file inside.
Please don't make this mistake. Such an omission can lose many potential developers and users. State up front, right below the mission statement, that the project is "free software" or "open source software", and give the exact license. A quick guide to choosing a license is given in the section called “Choosing a License and Applying It”, and licensing issues are discussed in detail in Chapter 9, Legal Matters: Licenses, Copyrights, Trademarks and Patents.
By this point, our hypothetical visitor has determined — probably in a minute or less — that she's interested in spending, say, at least five more minutes investigating this project. The next sections describe what she should encounter in those five minutes.
There should be a brief list of the features the software supports (if something isn't completed yet, you can still list it, but put "planned" or "in progress" next to it), and the kind of computing environment required to run the software. Think of the features/requirements list as what you would give to someone asking for a quick summary of the software. It is often just a logical expansion of the mission statement. For example, the mission statement might say:
To create a full-text indexer and search engine with a rich API, for use by programmers in providing search services for large collections of text files.
The features and requirements list would give the details, clarifying the mission statement's scope:
Searches plain text, HTML, and XML
Word or phrase searching
(planned) Fuzzy matching
(planned) Incremental updating of indexes
(planned) Indexing of remote web sites
Python 3.2 or higher
Enough disk space to hold the indexes (approximately 2x original data size)
With this information, readers can quickly get a feel for whether this software has any hope of working for them, and they can consider getting involved as developers too.
Visitors usually want to know how a project is doing. For new projects, they want to know the gap between the project's promise and current reality. For mature projects, they want to know how actively it is maintained, how often it puts out new releases, how responsive it is likely to be to bug reports, etc.
There are a couple of different avenues for providing answers to these questions. One is to have a development status page, listing the project's near-term goals and needs (for example, it might be looking for developers with a particular kind of expertise). The page can also give a history of past releases, with feature lists, so visitors can get an idea of how the project defines "progress", and how quickly it makes progress according to that definition. Some projects structure their development status page as a roadmap that includes the future: past events are shown on the dates they actually happened, future ones on the approximate dates the project hopes they will happen.
The other way — not mutually exclusive with the first, and in fact probably best done in combination with it — is to have various automatically-maintained counters and indicators embedded in the projects's front page and/or its developer landing page, showing various pieces of information that, in the aggregate, give a sense of the project's development status and progress. For example, an Announcements or News panel showing recent news items, a Twitter or other microblog stream showing notices that match the project's designated hashtags, a timeline of recent releases, a panel showing recent activity in the bug tracker (bugs filed, bugs responded to), another showing mailing list or discussion forum activity, etc. Each such indicator should be a gateway to further information of its type: for example, clicking on the "recent bugs" panel should take one to the full bug tracker, or at least to an expanded view into bug tracker activity.
Really, there are two slightly different meanings of "development status" being conflated here. One is the formal sense: where does the project stand in relation to its stated goals, and how fast is it making progress. The other is less formal but just as useful: how active is this project? Is stuff going on? Are there people here, getting things done? Often that latter notion is what a visitor is most interested in. Whether or not a project met its most recent milestone is sometimes not as interesting as the more fundamental question of whether it has an active community of developers around it.
The two notions of development status are, of course, related, and a well-presented project shows both kinds. The information can be divided between the project's front page (show enough there to give an overview of both types of development status) and a more developer-oriented page.
Don't be afraid of looking unready, and never give in to the temptation to inflate or hype the development status. Everyone knows that software evolves by stages; there's no shame in saying "This is alpha software with known bugs. It runs, and works at least some of the time, but use at your own risk." Such language won't scare away the kinds of developers you need at that stage. As for users, one of the worst things a project can do is attract users before the software is ready for them. A reputation for instability or bugginess is very hard to shake, once acquired. Conservativism pays off in the long run; it's always better for the software to be more stable than the user expected than less, and pleasant surprises produce the best kind of word-of-mouth.
The software should be downloadable as source code in standard formats. When a project is first getting started, binary (executable) packages are not necessary, unless the software has such complicated build requirements or dependencies that merely getting it to run would be a lot of work for most people. (But if this is the case, the project is going to have a hard time attracting developers anyway!)
The distribution mechanism should be as convenient, standard, and low-overhead as possible. If you were trying to eradicate a disease, you wouldn't distribute the medicine in such a way that it requires a non-standard syringe size to administer. Likewise, software should conform to standard build and installation methods; the more it deviates from the standards, the more potential users and developers will give up and go away confused.
That sounds obvious, but many projects don't bother to standardize their installation procedures until very late in the game, telling themselves they can do it any time: "We'll sort all that stuff out when the code is closer to being ready." What they don't realize is that by putting off the boring work of finishing the build and installation procedures, they are actually making the code take longer to get ready — because they discourage developers who might otherwise have contributed to the code, if only they could build and test it. Most insidiously, the project won't even know it's losing all those developers, because the process is an accumulation of non-events: someone visits a web site, downloads the software, tries to build it, fails, gives up and goes away. Who will ever know it happened, except the person themselves? No one working on the project will realize that someone's interest and good will have been silently squandered.
Boring work with a high payoff should always be done early, and significantly lowering the project's barrier to entry through good packaging brings a very high payoff.
When you release a downloadable package, give it a unique version number, so that people can compare any two releases and know which supersedes the other. That way they can report bugs against a particular release (which helps respondents to figure out if the bug is already fixed or not). A detailed discussion of version numbering can be found in the section called “Release Numbering”, and the details of standardizing build and installation procedures are covered in the section called “Packaging”.
Downloading source packages is fine for those who just want to install and use the software, but it's not enough for those who want to debug or add new features. Nightly source snapshots can help, but they're still not fine-grained enough for a thriving development community. People need real-time access to the latest sources, and a way to submit changes based on those sources.
The solution is to use a version control system — specifically, an online, publicly-accessible version controlled repository, from which anyone can check out the project's materials and subsequently get updates. A version control repository is a sign — to both users and developers — that this project is making an effort to give people what they need to participate. As of this writing, many open source projects use https://github.com/, which offers unlimited free public version control hosting for open source projects. While GitHub is not the only choice, nor even the only good choice, it's a reasonable one for most projects. Version control infrastructure is discussed in detail in the section called “Version Control”.
The same goes for the project's bug tracker. The importance of a bug tracking system lies not only in its day-to-day usefulness to developers, but in what it signifies for project observers. For many people, an accessible bug database is one of the strongest signs that a project should be taken seriously — and the higher the number of bugs in the database, the better the project looks. That might seem counterintuitive, but remember that the number of bug reports filed really depends on three things: the absolute number of actual software defects present in the code, the number of people using the software, and the convenience with which those people can report new bugs. Of these three factors, the latter two are much more significant than the first. Any software of sufficient size and complexity has an essentially arbitrary number of bugs waiting to be discovered. The real question is, how well will the project do at recording and prioritizing those bugs? A project with a large and well-maintained bug database (meaning bugs are responded to promptly, duplicate bugs are unified, etc.) therefore makes a better impression than a project with no bug database, or a nearly empty database.
Of course, if your project is just getting started, then the bug database will contain very few bugs, and there's not much you can do about that. But if the status page emphasizes the project's youth, and if people looking at the bug database can see that most filings have taken place recently, they can extrapolate from that the project still has a healthy rate of filings, and they will not be unduly alarmed by the low absolute number of bugs recorded.
Note that bug trackers are often used to track not only software bugs, but enhancement requests, documentation changes, pending tasks, and more. The details of running a bug tracker are covered in the section called “Bug Tracker”, so I won't go into them here. The important thing from a presentation point of view is just to have a bug tracker, and to make sure that fact is visible from the front page of the project.
Visitors usually want to know how to reach the human beings involved with the project. Provide the addresses of mailing lists, chat rooms, IRC channels (Chapter 3, Technical Infrastructure), and any other forums where others involved with the software can be reached. Make it clear that you and the other authors of the project are subscribed to these mailing lists, so people see there's a way to give feedback that will reach the developers. Your presence on the lists does not imply a committment to answer all questions or implement all feature requests. In the long run, probably only a fraction users will use the forums anyway, but the others will be comforted to know that they could if they ever needed to.
In the early stages of a project, there's no need to have separate user and developer forums. It's much better to have everyone involved with the software talking together, in one "room." Among early adopters, the distinction between developer and user is often fuzzy; to the extent that the distinction can be made, the ratio of developers to users is usually much higher in the early days of the project than later on. While you can't assume that every early adopter is a programmer who wants to hack on the software, you can assume that they are at least interested in following development discussions and in getting a sense of the project's direction.
As this chapter is only about getting a project started, it's enough merely to say that these communications forums need to exist. Later, in the section called “Handling Growth”, we'll examine where and how to set up such forums, the ways in which they might need moderation or other management, and how to separate user forums from developer forums, when the time comes, without creating an unbridgeable gulf.
If someone is considering contributing to the project, she'll look for developer guidelines. Developer guidelines are not so much technical as social: they explain how the developers interact with each other and with the users, and ultimately how things get done.
This topic is covered in detail in the section called “Writing It All Down”, but the basic elements of developer guidelines are:
pointers to forums for interaction with other developers
instructions on how to report bugs and submit patches
some indication of how development is usually done and how decisions are made — is the project a benevolent dictatorship, a democracy, or something else
No pejorative sense is intended by "dictatorship", by the way. It's perfectly okay to run a tyranny where one particular developer has veto power over all changes. Many successful projects work this way. The important thing is that the project come right out and say so. A tyranny pretending to be a democracy will turn people off; a tyranny that says it's a tyranny will do fine as long as the tyrant is competent and trusted. (See the section called “Forkability” for why dictatorship in open source projects doesn't have the same implications as dictatorship in other areas of life.)
http://subversion.apache.org/docs/community-guide/ is an example of particularly thorough developer guidelines; the LibreOffice guidelines at https://wiki.documentfoundation.org/Development are also a good example.
If the project has a written Code of Conduct (see the section called “Codes of Conduct”), then the developer guidelines should link to it.
The separate issue of providing a programmer's introduction to the software is discussed in the section called “Developer Documentation”.
Documentation is essential. There needs to be something for people to read, even if it's rudimentary and incomplete. This falls squarely into the "drudgery" category referred to earlier, and is often the first area where a new open source project falls down. Coming up with a mission statement and feature list, choosing a license, summarizing development status — these are all relatively small tasks, which can be definitively completed and usually need not be revisited once done. Documentation, on the other hand, is never really finished, which may be one reason people sometimes delay starting it at all.
The most insidious thing is that documentation's utility to those writing it is the reverse of its utility to those who will read it. The most important documentation for initial users is the basics: how to quickly set up the software, an overview of how it works, perhaps some guides to doing common tasks. Yet these are exactly the things the writers of the documentation know all too well — so well that it can be difficult for them to see things from the reader's point of view, and to laboriously spell out the steps that (to the writers) seem so obvious as to be unworthy of mention.
There's no magic solution to this problem. Someone just needs to sit down and write the stuff, and then, most importantly, incorporate feedback from readers. Use a simple, easy-to-edit format such as HTML, plain text, Markdown, ReStructuredText, or some variant of XML — something that's convenient for lightweight, quick improvements on the spur of the moment. This is not only to remove any overhead that might impede the original writers from making incremental improvements, but also for those who join the project later and want to work on the documentation.
One way to ensure basic initial documentation gets done is to limit its scope in advance. That way, writing it at least won't feel like an open-ended task. A good rule of thumb is that it should meet the following minimal criteria:
Tell the reader clearly how much technical expertise they're expected to have.
Describe clearly and thoroughly how to set up the software, and somewhere near the beginning of the documentation, tell the user how to run some sort of diagnostic test or simple command to confirm that they've set things up correctly. Startup documentation is in some ways more important than actual usage documentation. The more effort someone has invested in installing and getting started with the software, the more persistent she'll be in figuring out advanced functionality that's not well-documented. When people abandon, they abandon early; therefore, it's the earliest stages, like installation, that need the most support.
Give one tutorial-style example of how to do a common task. Obviously, many examples for many tasks would be even better, but if time is limited, pick one task and walk through it thoroughly. Once someone sees that the software can be used for one thing, they'll start to explore what else it can do on their own — and, if you're lucky, start filling in the documentation themselves. Which brings us to the next point...
Label the areas where the documentation is known to be incomplete. By showing the readers that you are aware of its deficiencies, you align yourself with their point of view. Your empathy reassures them that they don't face a struggle to convince the project of what's important. These labels needn't represent promises to fill in the gaps by any particular date — it's equally legitimate to treat them as open requests for help.
The last point is of wider importance, actually, and can be applied to the entire project, not just the documentation. An accurate accounting of known deficiencies is the norm in the open source world. You don't have to exaggerate the project's shortcomings, just identify them scrupulously and dispassionately when the context calls for it (whether in the documentation, in the bug tracking database, or on a mailing list discussion). No one will treat this as defeatism on the part of the project, nor as a commitment to solve the problems by a certain date, unless the project makes such a commitment explicitly. Since anyone who uses the software will discover the deficiencies for themselves, it's much better for them to be psychologically prepared — then the project will look like it has a solid knowledge of how it's doing.
Documentation should be available from two places: online (directly from the web site), and in the downloadable distribution of the software (see the section called “Packaging”). It needs to be online, in browsable form, because people often read documentation before downloading software for the first time, as a way of helping them decide whether to download at all. But it should also accompany the software, on the principle that downloading should supply (i.e., make locally accessible) everything one needs to use the package.
For online documentation, make sure that there is a link that brings up the entire documentation in one HTML page (put a note like "monolithic" or "all-in-one" or "single large page" next to the link, so people know that it might take a while to load). This is useful because people often want to search for a specific word or phrase across the entire documentation. Generally, they already know what they're looking for; they just can't remember what section it's in. For such people, nothing is more frustrating than encountering one HTML page for the table of contents, then a different page for the introduction, then a different page for installation instructions, etc. When the pages are broken up like that, their browser's search function is useless. The separate-page style is useful for those who already know what section they need, or who want to read the entire documentation from front to back in sequence. But this is not necessarily the most common way documentation is accessed. Often, someone who is basically familiar with the software is coming back to search for a specific word or phrase, and to fail to provide them with a single, searchable document would only make their lives harder.
Developer documentation is written by programmers to help other programmers understand the code, so they can repair and extend it. This is somewhat different from the developer guidelines discussed earlier, which are more social than technical. Developer guidelines tell programmers how to get along with each other; developer documentation tells them how to get along with the code itself. The two are often packaged together in one document for convenience (as with the http://subversion.apache.org/docs/community-guide/ example given earlier), but they don't have to be.
Although developer documentation can be very helpful, there's no reason to delay a release to do it. As long as the original authors are available (and willing) to answer questions about the code, that's enough to start with. In fact, having to answer the same questions over and over is a common motivation for writing documentation. But even before it's written, determined contributors will still manage to find their way around the code. The force that drives people to spend time learning a codebase is that the code does something useful for them. If people have faith in that, they will take the time to figure things out; if they don't have that faith, no amount of developer documentation will get or keep them.
So if you have time to write documentation for only one audience, write it for users. All user documentation is, in effect, developer documentation as well; any programmer who's going to work on a piece of software will need to be familiar with how to use it too. Later, when you see programmers asking the same questions over and over, take the time to write up some separate documents just for them.
Some projects use wikis for their initial documentation, or even as their primary documentation. In my experience, this works best if the wiki is actively maintained by a few people who agree on how the documentation is to be organized and what sort of "voice" it should have. See the section called “Wikis” for more.
If the infrastructure aspects of documentation workflow seem daunting, consider using https://readthedocs.org/. Many projects now depend on it to automate the process of presenting their documentation online. The site takes care of format conversion, integration with the project's version control repository (so that documentation rebuilds happen automatically), and various other mundane tasks, so that you and your contributors can focus on content.
If the project involves a graphical user interface, or if it produces graphical or otherwise distinctive output, put some samples up on the project web site. In the case of interface, this means screenshots or, better yet, a brief (4 minutes or fewer) video with subtitles or a narrator. For output, it might be screenshots or just sample files to download. For web-based software, the gold standard is a demo site, of course, assuming the software is amenable to that.
The main thing is to cater to people's desire for instant gratification in the way they are most likely to expect. A single screenshot or video can be more convincing than paragraphs of descriptive text and mailing list chatter, because it is proof that the software works. The code may still be buggy, it may be hard to install, it may be incompletely documented, but image-based evidence shows people that if one puts in enough effort, one can get it to run.
There are many other things you could put on the project web site, if you have the time, or if for one reason or another they are especially appropriate: a news page, a project history page, a related links page, a site-search feature, a donations link, etc. None of these are necessities at startup time, but keep them in mind for the future.
Where on the Internet should you put the project's materials?
A web site, obviously — but the full answer is a little more complicated than that.
Many projects distinguish between their primary public user-facing web site — the one with the pretty pictures and the "About" page and the gentle introductions and videos and guided tours and all that stuff — and their developers' site, where everything's grungy and full of closely-spaced text in monospace fonts and impenetrable abbreviations.
Well, I exaggerate. A bit. In any case, in the early stages of your project it is not so important to distinguish between these two audiences. Most of the interested visitors you get will be developers, or at least people who are comfortable trying out new code. Over time, you may find it makes sense to have a user-facing site (of course, if your project is a code library, those "users" might be other programmers) and a somewhat separate collaboration area for those interested in participating in development. The collaboration site would have the code repository, bug tracker, development wiki, links to development mailing lists, etc. The two sites should link to each other, and in particular it's important that the user-facing site make it clear that the project is open source and where the open source development activity can be found.
In the past, many projects set up the developer site and infrastructure themselves. Over the last decade or so, however, most open source projects — and almost all the new ones — just use one of the "canned hosting" sites that have sprung up to offer these services for free to open source projects. By far the most popular such site, as of early 2018, is GitHub (https://github.com/), and if you don't have a strong preference about where to host, you should probably just choose GitHub; many developers are already familiar with it and have personal accounts there. See the section called “Canned Hosting” for a more detailed discussion of the questions to consider when choosing a canned hosting site and for an overview of the most popular ones.
 The importance of
top-level domain names seems to be declining. A number of
projects now have just their name in the
.io TLD, for example, and don't
.org. I can't predict what the
brand psychology of domain names will be in the future, so
just use your judgement, and if you can get the name in
all the important TLDs, do so.
 They didn't manage to get gnome.com or gnome.net, but that's okay — if you only have one, and it's .org, it's fine. That's usually the first one people look for when they're seeking the open source project of that name. If they couldn't get "gnome.org" itself, a typical solution would be to get "gnomeproject.org" instead, and many projects solve the problem that way.
 Although GitHub is based on Git, a popular open source version control system, the code that runs GitHub's web services is not itself open source. Whether this matters for your project is a complex question, and is addressed in more depth in the section called “Canned Hosting”
 For a more thorough argument that bug reports should be treated as good news, see http://www.rants.org/2010/01/10/bugs-users-and-tech-debt/, which is about how the accumulation of bug reports does not represent technical debt (in the sense of https://en.wikipedia.org/wiki/Technical_debt) but rather user engagement.