The ruby-processing group exists to collect together projects that support creating and running processing sketches in ruby. It is also designed to hide the inevitably high bus factor of what is an essentially one man band, but I am trying hard to make it otherwise (including evolving the code). You could play your part…
JRubyArt is the closest to the original ruby-processing and provides a ruby implementation that approximates to the latest vanilla processing (but can be configured to not require a jruby install). However unlike ruby-processing it does not require a vanilla processing install.
Propane is a configuration free, complete version of ruby-processing (does not require installed vanilla processing) that depends on an installed jruby (is slightly more experimental however since a modified PApplet is required with jdk9+ propane may take over in future). Since propane-3.2.0, propane is compiled with jdk11, and thus jdk11 is a requirement.
PiCrate is a standalone version targetting the RaspberryPI, but it can be developed and run 64 bit linux, tested with Raspberry OS (32 bit) and Manjaro Arm (64 bit). Needs at least RaspberryPI3B+, currently works best on RaspberryPI4. Suggested ide geany.
My first degree was BSc hons Biochemistry from University of Surrey, I went on to specialize in xenobiotic metabolism (at first drugs, then industrial chemicals and pesticides). I later studied for a computer science degree with the Open University (BSc hons 2:1 but completed insufficient specific modules to be a named degree), course included some smalltalk but mainly java. Subsequently I dabbled a bit with C++, perl python, and even lisp, but got hooked on ruby, particulary ruby-processing. OS experience Windows-98 up to Windows-XP and mainly linux since 2004 (tried gentoo, fedora, even pardus) now using exclusively Archlinux and Mint (Debian). Since November 2012 I have been sole developer/maintainer of ruby-processing (did update for processing-2.0), and I have since developed JRubyArt and propane (for processing-3.0+) and ensured that jruby-18.104.22.168+ (with support from jruby group) continues to work with ruby-processing, and its descendants. More recently got RaspberryPI 3B+ and RaspberryPI 4 to let me check my PiCrate gem (processing in ruby on the PI). The current versions of propane, PiCrate and JRubyArt are based on the yet to be released processing4 but Vec2D and Vec3D are preferred to PVector and processing noise has been completely replaced with OpenSimplex2 noise.