There are 11 repositories under telegram-server topic.
Unofficial open source mtproto server written in golang with compatible telegram client.
Telegram Client Library To make it easier and faster for you to create programs that interact with the Telegram API, MTProto, TDlib, Telegram-bot-API with customizable features so that you can create bot / userbot / app (Dart / Flutter) programs on a large / business scale
MyTelegram is Telegram server side api implementation written in c#
An experimental Telegram Server implementation in Python
Telegram Bot which informs about Ubuntu Package upgrades written in go.
Personal telegram bot to work with the server
Caching proxy server for telegram bot api written in django.