So a while back I was playing around with a templating language based on APR. I've still been playing with it, off and on, and it's finally ready for a new release.
I've made a bunch of changes since the last version, including renaming it from "APR-Template" to "ETL" since this isn't actually a part of the APR project, switching from a hand rolled lexer and parser to a lexer based on re2c and a parser based on lemon, and the addition of some new features, like filters to html/xml/url encode output. This version also handles utf8 templates correctly, which is a nice bonus we got as part of the switch to re2c.
Note that from the users point of view, the fact that I use re2c and lemon is totally transparent, they generate regular old C code, which is shipped as part of the release tarball, so the transition from the old lexer/parser to the new one is purely a developer visible thing, other than the fact that the new way of doing things makes it way easier to add new features ;-)
It's still lacking a number of features, but it's far enough along that it can be used for basic tasks, and the groundwork is there for finishing up the remaining features I want to add.
Anyway, if you're looking for a template language to embed into your Apache HTTPD module or other APR based application, feel free to grab it at http://electricjellyfish.net/garrett/etl/etl-0.1.0.tar.gz. Feedback, as always, is more than welcome.