[Kanata](https://github.com/jtroo/kanata/) is a software keyboard remapper that aims to improve keyboard comfort and usability with advanced customization.
Keyboard remappers are a good alternative to running a custom keyboard with QMK/ZMK, and have two main advantages: they work on any keyboard, and you can configure them to launch any command or program you want, not just key presses.
On the other hand, you need to configure them on every PC/OS you're using your keyboard with, and all the processing is done on software on top of the OS, so there may be glitches and performance issues.