nimx and a bunch of others. At that time I didn't know what framework I'd want, only the requirements: Cross-platform, preferably native controls, internal and desktop drag&drop, extended clipboard support, rich text editor fields with possibilities of custom ranges, styles, and serialization, listboxes/grids with images and embedded controls.

I later decided on GTK3, not sure if it's the right idea in the long run. Nim's GTK3 bindings state:

> This package is only tested with 64 bit Linux currently.