Most active ports:
AIX
Darwin-Power-Macintosh
FreeBSD-alpha
FreeBSD-i386
HP-UX-9000-800
HP-UX-ia64
IRIX-IP32
Linux-alpha
Linux-i686
Linux-ia64
Linux-parisc64
Linux-ppc
Linux-x86_64
NetBSD-i386
OSF1-alpha
pocketpc-arm.exe
SunOS-sun4u
win32-x86.zip
Depends on computer access (remote access is welcome):
NetBSD-alpha
OpenBSD-alpha
OpenBSD-i386
If you provide me an account on another computer with decent gcc and unix like tools (bash, make, automake, ...), I can make new ports.