WWW.ZVENO.COM makes an open source Tcl XML parser and generator package. ACS 4 uses it in the package manager to parse config
files. It lets you make a DOM tree model as well as use an event driven
parser model, I believe.
There's some weird bug about how using tcl code which is its
own namespace has to be loaded into each thread separately in
AOLserver, I don't understand the issue, but you can look
at the source for the ACS 4 package manager and see what they are doing.
There's also some Java libraries which you could use if you
can figure out how to run Java from AOLserver.
