My favorite (and the one I find myself getting the most joy from using) is /, which I have bound to tangle and weave my currently-open project (dbus, yay) into

My favorite (and the one I find myself getting the most joy from using) is /, which I have bound to tangle and weave my currently-open project (dbus, yay) into /tmp, apply a stylesheet to the output of it, determine languages used within, embed Emscripten-compiled interpreters for the languages being used into the generated pages (its file system API is incredible, "I Can't Believe It's Not UNIX!"-worthy), and launch a Mozilla instance so I can interactively play with/debug my programs while reading their documentation in the same window. If this sounds like a convoluted REPL with fancier in-line documentation, you're kind of right. It's basically just interactive and automated literate programming, though. The rest of my bindings range from pretty simple (running an open project's tests, displaying results from the last 10 commits, etc.) to significantly more complex. I have a few different xkb layouts depending on what I'm doing, and a few different languages get dedicated ones, but for the ones I most-commonly use, they all share one.