This little gif demonstrates what it can do now: https://github.com/sedwards2009/extraterm/raw/master/docs/ed...
Some more demos of its features are here: https://github.com/sedwards2009/extraterm/blob/master/docs/t...
It is still early days for Extraterm although I use it myself daily (mostly on Windows and Linux). It too is built on Electron. It makes it possible to try out ideas relatively quickly and grants access to a megaton of 3rd party libraries and tools.
