For a few years I used each of Wily on a Sun box, then Acme SAC on Windows, and now hosted Inferno on Linux. I could use acme from plan9port, but I prefer Inferno because the whole environment gives me other nifty OS stuff like Inferno's shell sh and /env, which I make use of for the build tool I'm writing. The trickiest part of using Inferno is dealing with the different paths to files depending on whether you're running under emu (emu uses /n/local for files under host /, and / for files under host's /usr/inferno), or on the host (host uses / for files under emu's /n/local, and /usr/inferno for files under emu's /).

Using the mouse or keyboard is a rounding error compared to the time and errors I save by keeping the commands I use in per-directory guide files. I type out a command once, then later modify it slightly repeatedly to suit new needs, and highlight it and run it.

I've never found navigating to and selecting text with keyboard commands as fast and forthright and mindless as just moving the mouse and clicking to locate the cursor and select a range of text, and I used Emacs for 11 years. Also, since Acme binds common operations like cut, paste, and execute to mouse chords, I don't leave the mouse to do these things.

I don't dig candy-colored text, so the lack of syntax highlighting is a plus for me.