What framework is trac based on?

I just downlo开发者_如何学Caded this tracking system and curious what framework this great system uses?

Trac does not use any overarching external "framework". You can see its complete list of external dependencies (beyond a Python interpreter itself) in the setup.py file from the distribution:

    install_requires = [
        'setuptools>=0.6b1',
        'Genshi>=0.6',
    ],
    extras_require = {
        'Babel': ['Babel>=0.9.5'],
        'Pygments': ['Pygments>=0.6'],
        'reST': ['docutils>=0.3'],
        'SilverCity': ['SilverCity>=0.9.4'],
        'Textile': ['textile>=2.0'],
    },

If you're particularly interested in the HTTP side of things, take a look at the source to the trac.web module.