Actually it's not completely open_source.You can check the readme file.You have to get accepted as a coder by the other contributers in order to contribute.
I'd still consider it open source even if you aren't able to contribute to the official repo. If one wants to contribute but isn't permitted to update the main Epochtalk repository, they can just make a fork of Epochtalk and make their changes in their own repo. Open source just means that all the code is openly available to anyone who wishes to view it, it doesn't require that you're permitted to contribute to the official project though. Quote
Epochtalk is an open source project and we are planning to accept contributions. If you would like to contribute to Epochtalk please email [email protected].
