Unofficial Telegram Server
Please visit my new project Project Ferrite as I plan to maintain that one.
Telegram Server is an open source, server side implementation of Telegram API.
This project is currently being developed and only a small number of API calls work as this code is released at the beginning of the development. Some of the working parts are:
Our MTProto implementation works but does not include many security checks necessary yet. Therefore it is not recommended for any other uses other than experimental use.