An idea or suggestion of general technical interest should be mailed to the FreeBSD technical discussions mailing list. Likewise, people with an interest in such things (and a tolerance for a high volume of mail!) may subscribe to the FreeBSD technical discussions mailing list. See The FreeBSD Handbook for more information about this and other mailing lists.

If you find a bug or are submitting a specific change, please report it using the bug submission form. Try to fill-in each field of the bug report. Unless they exceed 65KB, include any patches directly in the report. If the patch is suitable to be applied to the source tree put [PATCH] in the synopsis of the report. When including patches, do not use cut-and-paste because cut-and-paste turns tabs into spaces and makes them unusable. When patches are a lot larger than 20KB, consider compressing them (eg. with gzip(1) or bzip2(1)) prior to uploading them.

After filing a report, you should receive confirmation along with a tracking number. Keep this tracking number so that you can update us with details about the problem.

See also this article on how to write good problem reports.

Changes to the documentation are overseen by the FreeBSD documentation project mailing list. Please look at the FreeBSD Documentation Project Primer for complete instructions. Send submissions and changes (even small ones are welcome!) using the same method as any other bug report.

An addition or change to the existing source code is a somewhat trickier affair and depends a lot on how far out of date you are with the current state of FreeBSD development. There is a special on-going release of FreeBSD known as “FreeBSD-CURRENT” which is made available in a variety of ways for the convenience of developers working actively on the system. See The FreeBSD Handbook for more information about getting and using FreeBSD-CURRENT.

Working from older sources unfortunately means that your changes may sometimes be too obsolete or too divergent for easy re-integration into FreeBSD. Chances of this can be minimized somewhat by subscribing to the FreeBSD announcements mailing list and the FreeBSD-CURRENT mailing list lists, where discussions on the current state of the system take place.

Assuming that you can manage to secure fairly up-to-date sources to base your changes on, the next step is to produce a set of diffs to send to the FreeBSD maintainers. This is done with the diff(1) command.

The preferred diff(1) format for submitting patches is the unified output format generated by diff -u.

% diff -u oldfile newfile

or

% diff -u -r -N olddir newdir

would generate a set of unified diffs for the given source file or directory hierarchy.

See diff(1) for more information.

Once you have a set of diffs (which you may test with the patch(1) command), you should submit them for inclusion with FreeBSD as a bug report. Do not just send the diffs to the FreeBSD technical discussions mailing list or they will get lost! We greatly appreciate your submission (this is a volunteer project!); because we are busy, we may not be able to address it immediately, but it will remain in the PR database until we do. Indicate your submission by including [PATCH] in the synopsis of the report.

If you feel it appropriate (e.g. you have added, deleted, or renamed files), bundle your changes into a tar file. Archives created with shar(1) are also welcome.

If your change is of a potentially sensitive nature, such as if you are unsure of copyright issues governing its further distribution then you should send it to Core Team <core@FreeBSD.org> directly rather than submitting as a bug report. The Core Team <core@FreeBSD.org> reaches a much smaller group of people who do much of the day-to-day work on FreeBSD. Note that this group is also very busy and so you should only send mail to them where it is truly necessary.

Please refer to intro(9) and style(9) for some information on coding style. We would appreciate it if you were at least aware of this information before submitting code.

In the case of a significant contribution of a large body work, or the addition of an important new feature to FreeBSD, it becomes almost always necessary to either send changes as tar files or upload them to a web or FTP site for other people to access. If you do not have access to a web or FTP site, ask on an appropriate FreeBSD mailing list for someone to host the changes for you.

When working with large amounts of code, the touchy subject of copyrights also invariably comes up. FreeBSD prefers free software licenses such as BSD or ISC. Copyleft licenses such as GPLv2 are sometimes permitted. The complete listing can be found on the core team licensing policy page.

We are always very happy to accept donations to further the cause of the FreeBSD Project and, in a volunteer effort like ours, a little can go a long way! Donations of hardware are also very important to expanding our list of supported peripherals since we generally lack the funds to buy such items ourselves.