As the person who maintains the install docs, here's where I'm at:
1) I just updated the install doc for Red Hat 9. I have not tested 5.0 install on Red Hat 8 recently but I believe it's still valid. Either platform is fine for a server, as long as you patch the critical security holes (kernel, ssh, ssl). It seems very likely that someone will continue producing rpms that work for stock Red Hat.
2) Install docs work for Debian sid, with breakage for some optional packages noted.
3) We should tie our decision of which platform to develop on to our decision of which platform to try and get included as standard on. The obvious targets are debian stable (via the whole path, so I guess this takes a few years to get there) or FreeBSD ports. Gentoo is another option but I think it has a smaller mindshare and less of a reputation as a server distribution. In order to make forward progress here, someone with regular access to a debian stable or FreeBSD machine needs to commit to doing the research and the work to get OpenACS and all prerequisites (AOLserver, tdom, etc) packaged. At that point, anybody who wants to add code to acs-core that requires new prerequisite (tdom, tclwebtest, etc) will, I propose, be responsible for getting that prereq added to the necessary packaging systems as a precondition.
