Forum OpenACS Development: Re: tcl with sockets ???
You might eventually want to write C code though, in order to take advantage of fancier AOLserver features. I'm not familiar with this, but people have used both AOLserver 3.x and 4.x to implement (high performance, I think) non-HTTP servers in AOLserver, e.g. SMTP, POP3, and DNS servers. Currently that requires patches to AOLserver 4.x, but people are working on integrating those patches in the stock AOLserver release. See in particular SourceForge Feature Requests 726288 and 973010.