Tilmann,
what you write is true, but the whole thing is not so easy as you think, at least not for beginners.
In order to try and install OpenACS 4.5 I had to download lots of different things (AOLserver, Postgres, libxml2, damontools, and other strange names...), issue very many commands (see
here) and hope all was right. Actually, although I struggled much, I could not succeed, so I insist now.
I am positively afraid that, in order to install 4.6, I will have to download new things (recent versions of programs, for instance) and issue many strange commands more: some (a lot) of which will most probably conflict with the existing situation.
>
...whereever you usually put your web projects...
I never had the chance to put any web project anywhere: I'm a beginner.
Luigi