Here are some information for developers.
Now Lightim is under active development.
You can join our Telegram Group: https://t.me/lightim_dev to discuss.
The project was founded by xtlsoft
Can be found on GitHub: https://github.com/lightim
We use PHP (async library is amphp) to develop Postic, Registry (two parts of server) and Messrec (Message Record Database).
Client side: PC: Electron, Mobile: Probably React Native
lightim & xtlsoft, 2016-2020