Neither dotLRN nor OpenACS will work under apache (well, you might be able to fight with mod_aolserver for a few months and
get it to run acceptibly but I certainly would not recommend it). I don't really think of dotLRN as being seperate from
OpenACS (rather it is a particular install of OpenACS).
You also don't seem to understand the difference between a
thread and a process. AOLServer is multithreaded, it creates threads within the server process to handle requests and typically those threads do not go away until the server process exits. ps on linux has the annoying -- not sure if you would call it a feature or a bug -- that it displays threads like they are processes, these don't really take any extra memory than is already taken by the server (note how they are all listed as being the same size and were all created at the same time -- thats because its all just the
same server process).