In a free software project that receives a lot of patches,^[121] keeping track of which patches have arrived and what has been decided about them can be a nightmare, especially if done in a decentralized way. Most patches arrive either as posts to the project's development mailing list or as a pull request submitted through the version control system, but there are a number of different routes a patch can take after arrival.

Sometimes someone reviews the patch, finds problems, and bounces it back to the original author for cleanup. This usually leads to an iterative process — all visible in a public forum — in which the original author posts revised versions of the patch until the reviewer has nothing more to criticize. It is not always easy to tell when this process is done: if the reviewer commits the patch, then clearly the cycle is complete. But if she does not, it might be because she simply didn't have time, or doesn't have commit access herself and couldn't rope any of the other developers into doing it.

Another frequent response to a patch is a freewheeling discussion, not necessarily about the patch itself, but about whether the concept behind the patch is good. For example, the patch may fix a bug, but the project prefers to fix that bug in another way, as part of solving a more general class of problems. Often this is not known in advance, and it is the patch that stimulates the discovery.

Occasionally, a posted patch is met with utter silence. Usually this is due to no developer having time at that moment to review the patch, so each hopes that someone else will do it. Since there's no particular limit to how long each person waits for someone else to pick up the ball, and meanwhile other priorities are always coming up, it's very easy for a patch to be ignored permanently without any single person intending for that to happen. The project might miss out on a useful patch this way, and there are other harmful side effects as well: it is discouraging to the author, who invested work in the patch, and it is discouraging to others considering writing patches.

The patch manager's job is to make sure that patches don't "slip through the cracks." This is done by following every patch through to some sort of stable state. The patch manager watches every issue tracker discussion, pull request, or mailing list thread that results from a patch posting. If it ends with a commit of the patch, he does nothing. If it goes into a review/revise iteration, ending with a final version of the patch but no commit, he creates or updates a ticket to point to the final version, and to any discussion around it, so that there is a permanent record for developers to follow up on later. In projects that use a patch queue management system^[122] or review tools,^[123] the patch manager can help encourage consistent usage of that tool by putting patches there and watching to make sure developers handle them there.

When a patch gets no reaction at all, the patch manager waits a few days, then follows up asking if anyone is going to review it. This usually gets a reaction: a developer may explain that she doesn't think the patch should be applied, and give the reasons why, or she may review it, in which case one of the previously described paths is taken. If there is still no response, the patch manager may or may not file a ticket for the patch, at his discretion, but at least the original submitter got some reaction. The true currency of open source projects is attention: people who can see that they are getting attention will keep participating, even if not every patch they submit lands.

Having a patch manager has saved the Subversion development team a lot of time and mental energy. Without a designated person to take responsibility, every developer would constantly have to worry "If I don't have time to respond to this patch right now, can I count on someone else doing it? Should I try to keep an eye on it? But if other people are also keeping an eye on it, for the same reasons, then we'd have needlessly duplicated effort." The patch manager removes the second-guessing from the situation. Each developer can make the decision that is right for her at the moment she first sees the patch. If she wants to follow up with a review, she can do that — the patch manager will adjust his behavior accordingly. If she wants to ignore the patch completely, that's fine too; the patch manager will make sure it isn't forgotten.

Because this system works only if people can depend on the patch manager being there without fail, the role should be held formally. In Subversion, we advertised for it on the development and users mailing lists, got several volunteers, and took the first one who replied. When that person had to step down (see the section called “Transitions”), we did the same thing again. We've never tried having multiple people share the role, because of the communications overhead that would be required between them; but perhaps at very high volumes of patch submission, a multiheaded patch manager might make sense.

In software projects, "translation" can refer to two somewhat different things. It can mean translating the software's documentation into other languages, or it can mean translating the software itself — that is, having the program display errors and help messages in the user's preferred language. Both are complex tasks, but once the right infrastructure is in place, they are largely separable from other development. Because the tasks are similar in some ways, it may make sense, depending on your project, to have a single translation manager handle both, or it may be better to have two different managers. (Note also that specialized infrastructure is available to help make the translation process more efficient; see the section called “Translation Infrastructure” for more on this.)

In the Subversion project, we had one translation manager handle both. He did not actually write the translations himself, of course — he might help out on one or two, but would need to speak more than ten languages fluently in order to work on all of them! Instead, he managed teams of other translators: he helped them coordinate among each other, and he coordinated between the translation teams and the rest of the project.

Part of the reason the translation manager is necessary is that translators are a different demographic from developers. They sometimes have little or no experience working in a version control repository, or indeed with working as part of a distributed team at all. But in other respects they are often the best kind of participant: people with specific domain knowledge who saw a need and chose to get involved. They are usually willing to learn, and enthusiastic to get to work. All they need is someone to tell them how. The translation manager makes sure that the translations happen in a way that does not interfere unnecessarily with regular development. He also serves as a sort of representative of the translators as a unified body, whenever the developers must be informed of technical changes required to support the translation effort.

Thus, the position's most important skills are diplomatic, not technical. For example, in Subversion we had a policy that all translations should have at least two people working on them, because otherwise there is no way for the text to be reviewed. When a new person shows up offering to translate Subversion to, say, Malagasy, the translation manager has to either hook him up with someone who posted six months ago expressing interest in doing a Malagasy translation, or else politely ask the person to go find another Malagasy translator to work with as a partner. Once enough people are available, the manager sets them up with the proper kind of commit access, informs them of the project's conventions (such as how to write log messages), and then keeps an eye out to make sure they adhere to those conventions.

Conversations between the translation manager and the developers, or between the translation manager and translation teams, are usually held in the project's original language — that is, the language from which all the translations are being made. For many free software projects, this is English, but it doesn't matter what it is as long as the project agrees on it. (English is probably best for projects that want to attract a broad international development community, though.)

Conversations within a particular translation team usually happen in their shared language, however, and one of the other tasks of the translation manager is to set up a dedicated mailing list for each team. That way the translators can discuss their work freely, without distracting people on the project's main lists, most of whom would not be able to understand the translation language.

Keeping software documentation up-to-date is a never-ending task. Every new feature or enhancement that goes into the code has the potential to cause a change in the documentation. Also, once the project's documentation reaches a certain level of completeness, you will find that a lot of the patches people send in are for the documentation, not for the code. This is because there are many more people competent to fix bugs in prose than in code: all users are readers, but only a few are programmers.

Documentation patches are usually easier to review and apply than code patches. There is little or no testing to be done, and the quality of the change can be evaluated quickly just by examination. Since the quantity is high, but the review burden fairly low, the ratio of administrative overhead to productive work is greater for documentation patches than for code patches. Furthermore, most of the patches will probably need some sort of adjustment, in order to maintain a consistent authorial voice in the documentation. In many cases, patches will overlap with or affect other patches, and need to be adjusted with respect to each other before being committed.

Given the exigencies of handling documentation patches, and the fact that the codebase needs to be constantly monitored so the documentation can be kept up-to-date, it makes sense to have one person, or a small team, dedicated to the task. They can keep a record of exactly where and how the documentation lags behind the software, and they can have practiced procedures for handling large quantities of patches in an integrated way.

Documentation managers also serve another important purpose: they may be the only people in the project who regularly review the documentation from top to bottom, and thus are in a position to notice obsolete or redundant material, independently of any particular change.

Of course, none of this prevents other people in the project from applying documentation patches on the fly, especially small ones, as time permits. And the same patch manager (see the section called “Patch Manager (or Pull Request Manager)”) can track both code and documentation patches, filing them wherever the development and documentation teams want them, respectively. (If the total quantity of patches ever exceeds one human's capacity to track, though, switching to separate patch managers for code and documentation is probably a good first step.) The point of a documentation team is to ensure that there are people who think of themselves as responsible for keeping the documentation organized, up-to-date, and consistent with itself. In practice, this means knowing the documentation intimately, watching the codebase, watching the changes others commit to the documentation, watching for incoming documentation patches, and using all these information sources to do whatever is necessary to keep the documentation healthy. If the documentation is kept in a wiki, then of course the wiki's "watch changes" feature can be very important to the documentation managers, since (depending on the wiki's edit policy) changes may land without going through a pre-change review process.

Bug report growth is proportional to user base growth, rather than to the number of actual defects in the software. That is, the number of tickets in a project's bug tracker grows in proportion — albeit usually non-linear proportion — to the number of people using the software.^[124] Therefore, even as you fix bugs and ship an increasingly robust, mature program, you should still expect the number of open tickets to grow essentially without bound. The frequency of duplicate tickets will thus also increase, as will the frequency of incomplete or poorly described tickets.

An issue manager^[125] helps cope with this situation by watching what goes into the database, and periodically sweeping through it looking for specific problems. Their most common action is probably to fix up incoming tickets, either because the reporter didn't set some of the form fields correctly, or because the ticket is a duplicate of one already in the database. Obviously, the more familiar an issue manager is with the project's bug database, and with the issue-tracking software's user interface and APIs, the more efficiently she will be able to detect and handle duplicate tickets. This is why it is often good to have a few people specialize in the bug database, instead of everyone trying to do it ad hoc. Although every developer in the project needs a certain basic level of competence in manipulating the issue tracker, having a few specialists becomes increasingly important as the project matures. When a project tries to spread collective responsibility for the bug database across everyone, no single individual acquires a deep enough expertise in the content of the database or the tracker's features.

Issue managers can help map between tickets and individual developers. When there are a lot of bug reports coming in, not every developer may read the ticket notification mailing list with equal attention. However, if someone who knows the development team is keeping an eye on all incoming tickets, then she can discreetly direct certain developers' attention to specific bugs when appropriate. Of course, this has to be done with a sensitivity to everything else going on in development, and to the recipient's desires and temperament. Therefore, it is often best for issue managers to be developers themselves.

Depending on how your project uses the ticket tracker, issue managers can also shape the database to reflect the project's priorities. For example, in Subversion we scheduled tickets into specific future releases, so that when someone asks "When will bug X be fixed?" we could say "Two releases from now," even if we can't give an exact date. The releases are represented in the ticket tracker as target milestones (something most ticket trackers support). As a rule, every Subversion release has one major new feature and a list of specific bug fixes. We assigned the appropriate target milestone to all the tickets planned for that release (including the new feature — it got a ticket too), so that people could view the bug database through the lens of release scheduling. These targets rarely remain static, however. As new bugs come in, priorities sometimes get shifted around, and tickets must be moved from one milestone to another so that each release remains manageable. This, again, is best done by people who have an overall sense of what's in the database, and how various tickets relate to each other.

Another thing issue managers do is notice when tickets become obsolete. Sometimes a bug is fixed accidentally as part of an unrelated change to the software, or sometimes the project changes its mind about whether a certain behavior is buggy. Finding obsoleted tickets is not easy: the only way to do it systematically is by making a sweep over all the tickets in the database. But full sweeps become less and less feasible over time, as the number of tickets grows. After a certain point, the only way to keep the database sane is to use a divide-and-conquer approach: categorize tickets immediately on arrival and direct them to the appropriate developer's or team's attention. The recipient then takes charge of the ticket for the rest of its lifetime, shepherding it to resolution or oblivion as necessary. When the database is that large, the issue manager becomes more of an overall coordinator, spending less time looking at each ticket herself and more time getting it into the right person's hands.