I'm looking into using a flash (xmlsockets) gateway to implement low latency connections between the browser and the server (Aolserver), in short, an implementation of COMET using a flash component.
I must admit that creating a socket server in AOLserver is not as straightforward as say in Apache with PHP or CGI perl but my research has led me to a number of different (possibly unrelated but potentially usefull) things.
Memcached : Someone has written a tcl api to memcached. Memcached caches db requests for clusters of AOLservers. It can run as a daemon on an unused server and allow several clustered web servers to share a cache of db requests. I was particularly intrigued that LiveJournal .com uses it with positive results. Dave suggests that it would be neat if this could be augmented into ns_cache.
Naviserver : I've known for sometime that there is a fork of AOLServer. I just noticed that they have lots of potentially useful modules. Some of these are familiar AOLServer modules. I would be interested to find out if any of these modules will work on AOLServer 4.0.10 and 4.5. Another intriguing question is whether OpenACS can run on NAVISERVER.