One of Carl's other project - She is frozen in time, what a beauty she is. The clones of her are nothing close. Carl Sassenrath is an outstanding figure in tech, unknown to many.
I'm part of Team Red, working on Rebol's successor (https://www.red-lang.org/). We have a number of old Rebolers, but also a lot of new faces, and we're having a great time carrying the torch forward. We still have a lot of work to do, but by the end of the year we should have feature parity with R2, not to mention all the new features Red has, like a compiler, reactive system, Android support, and native GUIs.
It's very similar to Rebol and is under active development. If you like Rebol and haven't tried Red, it's worth taking a look:
which is a spreadsheet in 17 lines of code using the inbuilt reactive system.
https://github.com/metaeducation/ren-c
In fact there was a Rebol conference only last month - http://2019.reb4.me/