https://tic80.com/ (lua, open source - you can pay for the binaries or build it yourself)

https://liko-12.github.io/ (lua, open source, I haven't used this much, but it seems nice)

https://github.com/ftsf/nico (nim, open source. Not quite the same as the others, there's no IDE, etc. But it's a library with an API similar to PICO)