Acme [1]

It steps back from the “customize everything” mantra, believing that approach leaves users with an underdeveloped essential system. But it still has two major APIs: one for window manipulation [2], the other for text-based integration with the surrounding system via plumber [3].

All textual CLI tools (that is, those without pseudographics) work by default and are the heart of its style.

I use Acme for everything except web browsing (although most links are still managed by Acme).

[1]: http://youtu.be/dP1xVpMPn8M

[2]: http://9p.io/magic/man2html/4/acme

[3]: http://9p.io/sys/doc/plumb.html