I actually recently had to install SBCL on my OS X 10.4 (Tiger) box. Here's how it went:
1. Grab from the Downloads folder.
2. Build.
3. Bombs during building because SBCL now relies on a link symbol which doesn't exist in Tiger. Apparently all Mac Lisp users are require to be 10.5 Leopard users.
4. Swear a bit.
5. Search the web.
6. Find lots of people swearing also, no answers.
7. Try CVS.
8. Build.
9. Bombs during build.
10. More swearing.
11. Start hunting through earlier versions of SBCL.
12. About 10 downloads later (and they take a lot of time each to download and build until it fails), finally find one which doesn't rely on the symbol.
1. Grab from the Downloads folder.
2. Build.
3. Bombs during building because SBCL now relies on a link symbol which doesn't exist in Tiger. Apparently all Mac Lisp users are require to be 10.5 Leopard users.
4. Swear a bit.
5. Search the web.
6. Find lots of people swearing also, no answers.
7. Try CVS.
8. Build.
9. Bombs during build.
10. More swearing.
11. Start hunting through earlier versions of SBCL.
12. About 10 downloads later (and they take a lot of time each to download and build until it fails), finally find one which doesn't rely on the symbol.
13. Am now running SBCL.
All told, about eight hours.