I have tested with AOLServer 4.0.3 and 4.0.5, Tcl 8.4.3, 8.4.4, 8.4.5 and 8.4.6, Postgres 7.3.5 and 7.4.2 (but not tested with 7.3.6) and all work fine (in the sense that I can
install from scratch, and create content without encountering
any errors -- I did not test for concurrency problems or
failure under load for example). I tend to upgrade whenever there is a new release to see that things work.
I don't run nsopenssl on the test servers though.
For reference the place in the docs we track this is the version compatibility matrix and the source document for that page is acs-core-docs/www/xml/install-guide/compatibility.xml