Open-Source Finance Tools

I woke up early this morning, so had a little time to myself. I decided that looking in to open-source personal finance tools would be a productive use of that time. Why? Who knows?

The strongest candidate may be Actual Budget (GitHub / Website). Although, trying to get my head around how to use it properly will take some time. I also looked at Firefly III, briefly. Along with some others. I need to spend more time with Firefly, and Skrooge is also on my list still to check out.
Could I use a simple spreadsheet? Absolutely. But it's nice to see what's out there.

How do you track your personal finances? I'd love to know.