[virmundi]

There are a few options.

http://alternativeto.net/software/electron/

One thing about these is that Electron can be optimized. I believe that one of the Visual Studio tools uses it and has dramatically lower memory than slack. Slack just doesn't try to improve performance.

[noloblo]

Like to see Alternatives to electron as well - even super optimized electron on code Atom and Google Chrome are quite heavy on a MacBook Air