Sounds like you're coming from having experience with Rebol2 (feel free to edit your post to add more background... I moved it over here to Introductions).
You probably like PARSE (?). There's a lot happening with UPARSE, here, but... it's early yet for the design.
Beware The Reasons Not To Use Ren-C 
It is not a production system--it is organic and constantly changing. Desktop builds are kept working but the long term priorities are in the browser, and testing in the browser too...
What I can hopefully promise to those who get involved in using it and designing it is that there will be interesting and novel techniques to enjoy.
What I can definitely promise is that if your objective is to get a task done and you find churn and seemingly endless design debate to be annoying and not thought-provoking... you will be unproductive and hate this project. If it will ever be in a state one would want as a "product" that would be years from now--and I have no promises that day will ever actually come.
My offering to some is that if their source is public and has reasonable tests that run on GitHub or wherever (to which I am given commit access)...that I will take on some responsibility for keeping your source in sync with changes. I can't do everything--and it may be that some features just go away entirely. But it can make it less of a problem when things change.
I'm building a C GUI application with GTK and Ren-C
There was a time when there was a (bad) CMake-based .lib and .a packaging process for Ren-C. It was used by Ren Garden, a Qt app.
Right now the only "lib" packaging (without a main()) that's really going is the web version. I'd like to revive Ren Garden, and it would certainly be nice if someone could help get the GitHub CI to build those lib packages and get things running.
But really, I want to temper expectations. I'm attacking kind of the foundational design issues, and that means a lot of mess and flux. There are comments and so some hope of understanding it...but things get out of date.
Help from co-designers who want to be involved is very welcome. But the scope is simply sprawling at this point. Serving users is nigh impossible...and even just having the handful of users who've been around for the ride for years is beyond what I can devote to an unpaid hobby.