FreeBSD
Download the most recent *.tbz file found here, and use the "pkg_add" utility, as root, to install it. After installation, the executable will be found at /usr/local/bin/M2.
- Macaulay2-1.2-i386-FreeBSD-7.1-RELEASE.tbz (8081276 bytes) [2009 February 9 19:35:17 GMT]