Interesting technologies...

A couple of interesting technologies (in no particular order) that I haven't gotten a chance to check out yet but have been meaning to...

JXPath - Allows you to access JavaBeans via XPath

XMLBeans - XML to JavaBean binding library, it's supposed to have some XPath/XQuery support in it

Subversion - Seems to be the most popular revision control system nowadays

Buildix - Subversion, Trac, and CruiseControl all bundled together into a single LiveCD

Genshi - As the author says, "A toolkit for stream-based generation of markup for the web." It seems like a pretty decent and modern templating tool for python, appears to be XML only though.

Janino - An embedded Java compiler. Doesn't even seem to need source code to reside on the disk.

What other interesting technologies are out there that people are interested in but haven't yet gotten a chance to explore?