[Kyrio]

Just for clarification, Aseprite is "source-available": you're free to browse [1], clone and build the source for your own usage as long as you don't redistribute your build. There's even a tutorial for it. Official builds, of course, are paid.

[1] https://github.com/aseprite/aseprite

[mkesper]

Being able to distribute your builds and improvements is one of the essential freedoms of Free Software.

[Kyrio]

Aseprite is not free software. But it is not "closed-source" either, hence my clarification.