Hello, Boron author here. I look in on the Ren-C project once a year or so to see what's going on. A few times I have considered joining this forum but for various reasons have not done so. Since you have made space for similar projects, now seems like a good time to touch base.
Boron is my daily driver for scripting and has been in a stable period for years. Bugfix releases occur roughly once per year. I should have been making release announcements on the mailing list, but as there is no community of active users I didn't bother. To exercise the language I have used it in the xu4 project to replace the XML configuration and scripting.
The next period of change may include support for static strings (ala AltScript), optimized path! storage, and reworking the evaluator to support yielding.
Games and graphics are an interest of mine so the Boron-GL project is where I experiment with GUIs, shaders, and such. Some of the work on xu4 such as font rendering and the Faun library will make it's way into Boron-GL. The GL code was part of the main Boron repository until the end of 2019.