Major components:

• Dictionaries: These used to be python dictionaries, but memory usage was too high, so they were replaced with a sqlite back end and a short class providing all the dictionary functionality I used. They map compatibility characters, radicals, phonetics, definitions, etc.
• Request handler: relatively standard code for handling requests for definition and cross-reference pages. Uses plain Twisted to minimize external dependencies.
• Rewriting Proxy: this is the difficult one.