Brett Terpstra, revisiting the “doing” CLI:

I haven’t written much about doing since then, but I continue to use it daily. It’s come a long way. It not only creates rich logs of my time at my computer, it also handles time tracking and reporting and integrates with my system via LaunchBar, various automations, and GeekTool. You know how git log can be really useful after a long night of hacking, or a few days of being away? This is that, but for everything else, and it’s brimming with handy features.

If you want to quickly jot down what you’ve been doing using the command line, I’ve not found a better way to do it than with doing. I’ve been using it for years.