Another Trillian user chiming in.

They are working mainly on their own server and Trillian for web, but the desktop version is still alive https://trillian.im/news/

Trillian isn't dead though. I still use it, despite the internet becoming more and more of a walled garden. Trillian still works just fine with Google hangouts, and facebook messenger too, as long as it's not a group chat.

I still use Trillian

I hate what Google did to GTalk and Hangouts