You can download source or binary packages:

RPM GNU/Linux i586 FreeBSD 4.x i586	RPM packages contain binary version of the development chain. These packages can be installed on any GNU/Linux i586 system (libc 2.x). You may eventually install them on a FreeBSD 4.2 i586 system if you have the Linux compatibility module. Choose this method if you want to quickly install the tools and avoid to have to compile them from the sources.
EXE Windows 98 Windows 2000 Windows XP	EXE files contain Binary packages for Windows. These packages can be installed on any Windows 95, 98, NT, 2000, XP i586 system. Choose this method if you want to quickly install the tools, or if you don't have Cygwin to rebuild the tools from the sources.
Sources GNU/Linux Solaris Mac OS X	Installation from the sources requires that you get the sources of various GNU packages. The FSF packages contain the 68HC11/68HC12 port but it is recommended to apply several patchs that fix problems found recently. You then have to compile the whole set. Use the source, Luke Choose this method if your host is not supported by the binary packages, or if you are interested in looking at the sources. Beware that this is not trivial unless you are familiar with building the GNU compiler already.