I ran my development server on a sparc 10 (dual 50 mhz!) w/128MB ram. I'd consider that pretty close to minimum, memory wise. (Especially since part was taken up by emacs. :) Caching all the tcl procs alone was close to 20 MB on a default 3.2.5 install; I imagine 4.x is more. Move the packages you don't use somewhere else, and get more ram.