Haps.at is a project mainly written in PYTHON and JAVASCRIPT, it's free.
A sample Tornado site
Haps.at is just an example Tornado web site, utilizing several really basic implementations of asynchronous API libraries.
It depends on tornado (http://github.com/facebook/tornado) and torn (http://github.com/joshmarshall/torn)
You can start it with python start.py in the main directory, but until you set the API keys in a settings_local.py (or haps/settings.py) it won't actually do much.
Platforms used (i.e. keys needed):