Linux linux OK on all versions I've tried back to Red Hat 6.1. Solaris solaris9lfs OK in Solaris 9 on Sparc. Not tested on Intel or in other Solaris releases. Solaris solaris9_74 OK in Solaris 9 on Sparc. Not tested on Intel or in other Solaris releases. HP-UX Tested OK on HP-UX 11.11 PA-RISC and 11i v2 IA64. FreeBSD Tested OK on Intel back to FreeBSD 3.3. NetBSD OK on Intel in NetBSD 2.0.3. LFS apparently not ready in NetBSD 1.x. OpenBSD Tested OK on Intel back to OpenBSD 2.5 Mac OS X Tested OK on Mac OS X 10.3.9 and later. UnixWare Tested OK on SCO UnixWare 7.1.4. AIX LFS should work but not tested, I have no access. IRIX 6.5 LFS requires changing all APIs to blah64().