I happened to stumble across HAML, an interesting and beautiful way to mark up contents and write templates for HTML.
Since I use Python and Django for my web develo
You may be interested in Plim. It's a mature python port of Slim.
This doesn't actually answer your question, but the CSS component of HAML, SASS, can be used freely with any framework. I'm using it right now with Django.
My project, PyHAML, is a Mako preprocessor that gives you very HAML-like syntax. Some of the Ruby doesn't translate very well to Python, so there are some differences, but the spirit is the same.
Daniel Skinner's project (mentioned above) seems to have been renamed to DMSL. It seems very powerful, emulates HAML but allows you to use python functions, lambdas, comprehensions etc in it's syntax: https://github.com/dasacc22/dmsl
I just made this http://github.com/fitoria/django-haml it's still in very early stage but it works.
I'm not sure what the status is of the GHRML bit as I only recently was looking into it. Can't find a repo for it, original developer doesn't have time for it anymore and maintenance was picked up by someone else with an interest in the project. Any extra info on this would be helpful.
Unfortunately, as these things go, I started writing my own HAML style processor ;)
http://dasacc22.wordpress.com/2010/05/03/python-implementation-of-haml/
It's in no way fit for production use at the moment (its literally a 4 day old infant now but like 60+hours crammed in those 4 days) but anyone interested may check it out here. It has a range of features already implemented that make it useful as a toy, and as I clean up the codebase over the next week, I hope to see it replace all my custom XSLT/xpath extensions and templates I have.