Versions of OpenBSD

Developers from around the world are continually making minor changes to the master OpenBSD source code repository. If you download the OpenBSD source code in the morning and download it again in the afternoon, you'll get two slightly different versions of the source code. This makes the traditional release numbering used by proprietary software less than practical. At any given moment, you can get a few different versions of OpenBSD: releases, -current, -stable, and snapshots.

Current

OpenBSD-current is simply the most recent development version of OpenBSD and contains code that is just making its public debut. OpenBSD-current is where much initial public review takes place and, at times, -current sees radical changes of the sort that give experienced systems administrators headaches. If a change in current temporarily breaks Web browsers, games, and database programs running on -current, but the change is for the long-term good, that's perfectly fine. These programs will work again before the next release of OpenBSD, but there's no requirement to have every program working perfectly at all times.

OpenBSD-current is available to the public at large, but it is intended for use by developers, testers, and interested parties. Support for generic UNIX user questions about -current is rather slim, because users are expected to be able to read the source code, fix problems, and contribute their work back to the community. If you can't read C, shell, and Perl, or don't feel like debugging your computer whenever something behaves in a manner you don't expect, or just don't like being left hanging until some volunteer somewhere finds the time to fix something that broke, -current is not for you.

Current is expected to work at all times, however. While it might break on occasion, those breaks are considered serious problems, and the OpenBSD team loses sleep over them. You might have to recompile your Web browser, but the project team requires a functioning core operating system at all times.

So, with all this, why would you want to run -current? One excellent reason to run -current is to test the operating system in your environment. If your new OpenBSD-current system panics under certain conditions, the OpenBSD group wants to know about it. You certainly run a risk by doing this, but the only way the operating system can be enhanced is when volunteers test the improvements in a variety of environments. If you can provide a good bug report, the developers want to hear about your crash.

If this doesn't sound like your idea of a good time, then don't run -current.

Snapshots

Every few days, the OpenBSD team builds a release from the latest -current code and puts it up on a FTP server. This interim release is a snapshot and is identified only by the date it is made available. There's nothing special about a snapshot, as compared to -current; it's just the state of -current at such-and-such a time. While the developers make a reasonable effort to not build a snapshot on a day that -current is utterly unusable, it may have any of the usual problems you'll see in tracking -current. There is no real quality-assurance process for snapshots.

Snapshots are mainly provided for installation convenience. It's much easier to upgrade to the latest OpenBSD-current from the most recent snapshot than it is to upgrade to -current from the most recent release.

Releases

Every six months, the pace of OpenBSD-current development is deliberately slowed. New features are polished and thoroughly tested, and public requests are made for beta testers of the latest snapshots. When the OpenBSD team is satisfied as to the quality of the software, a CVS tag (see CVS) is laid down, and a high-quality snapshot is built from that tag. This snapshot is called a release and is issued a number. This is almost certainly what you initially installed.

OpenBSD releases are numbered sequentially, starting with 2.0 and incrementing .1 with every release. Unlike most software products, a .0 release has no special meaning; it's just a point along a long path.

Once you have a release installed, you can start to follow the OpenBSD-stable patch branch.

Stable

OpenBSD-stable is simply OpenBSD-release with very minor patches. These patches are generally the "errata" for the release, including security fixes, things that are of great importance, or things that affect a lot of people. OpenBSD-stable is expected to be calm and reliable, requiring little user attention. According to Theo de Raadt, "The -stable tree must never get worse. It must never break. The fixes must be simple, even if hackjobs. They must not fail." This is an excellent choice for a production environment.

The only way to get OpenBSD-stable is to update the system from source. You can get effectively the same OS as -stable by applying the errata for a release, however.

Which Version Should You Use?

This release system gives users the best features of open source development and commercial releases. As a user, you have access to both the bleeding-edge experimental code and the stable, polished releases. You have everything you need to choose which release you want.

If you're running OpenBSD in a production environment, either use a release with the security errata or track stable.

If you're a network administrator evaluating OpenBSD for use in a production environment, install the version you plan to use — almost certainly a release with the security errata, or perhaps stable.

If you're just learning UNIX, use a release and apply the security errata.

If you're an operating system developer or experienced programmer, feel free to jump right into current. You should be able to handle any problems you encounter or use those problems as an excuse to expand your knowledge of UNIX programming.

Lastly, if you're a hobbyist, you can run anything! Just remember the limitations of the branch you're using. A release is a good place to start, but you can gradually upgrade your system to stable and then to current as your OpenBSD, UNIX, and programming understanding expands.