Telegram is not free software.
First, let me say that there is nothing wrong with the server-side code being
proprietary.
https://www.gnu.org/philosophy/network-services-arent-free-or-nonfree.html
The issue with Telegram is its CLIENT. The client is NOT free software. It
is an Electron app, and Electron includes Chromium code. Chromium depends on
a precompiled blob that nobody can find the source code for yet. Read more
at
https://lists.gnu.org/archive/html/libreplanet-discuss/2017-01/msg00001.html.
