There are multiple levels or tiers of Mozilla build "support". These tiers represent the shared priorities of the Mozilla project.
Tier-1 platform refers to platforms that are the primary focus for development. Build errors, performance regressions, and other major problems on these platforms are considered showstoppers that will cause a change to be immediately reverted. These are also the platforms that show up on the Firefox tinderbox page, and run on the Mozilla try-server. The tier-1 platforms are:
- Android Linux/ARMv7 and ARMv6 (gcc)
- Linux/x86 and x86-64 (gcc)
- OS X/x86 and x86-64 (clang)
- Windows/x86 (msvc)
- Windows Metro/x86 (msvc)
Tier-2 platforms are those platforms that the Mozilla community actively maintains. Breakage or regressions in these platforms does not immediately close the tree; developers who break these platforms are expected to work with platform maintainers to fix problems, and may be required to back out if a fix cannot be found:
- Android Linux/x86 (gcc)
Tier-3 platforms have a maintainer or community which attempt to keep the platform working. These platforms may or may not work at any time, and often have little test coverage:
- Windows/x86-64 (msvc)
- Linux on various CPU architectures including ARM, PPC, 68k — maintained by various Linux distributions
- OpenSolaris/x86&SPARC — maintained by Simon.Jin <[email protected]> and Ginn.Chen <[email protected]>
- OS/2 (gcc) — maintained by Rich Walsh, Dave Yeo, Walter Meinl, and Peter Weilbacher
- OS X/ppc (gcc) — maintained by Cameron Kaiser
- FreeBSD (gcc) — maintained by Jan Beich
- OpenBSD (gcc) — maintained by Landry Breuil
- Darwin/X11 — maintained by Jeremy Huddleston
- Windows/x86 and x86-64 (mingw gcc) — maintained by Jacek Caban — some features are disabled because they require MS COM or the w32api project doesn't expose the necessary Windows APIs
Most Mozilla developers do not have access to non-tier-1 platforms so any bug reports against non-tier-1 platforms should be overflowing with information to help the owner of the bug determine the cause of the problem and the proper solution. If you can provide a patch and/or verify that the developer's patches work for your platform, that would help a lot towards getting your bugs fixed and checked into the tree.