Sadly, Albert Rich, the author of Rubi passed away on August 11, 2023. Albert had been highly active in developing another release of Rubi.
This release are the untouched files from Albert's computer which were rescued by David Stoutemyer and mailed to me on a memory stick.
We considered making a number of bug fixes to this release, however I feel it's best if we have a release of Albert's final version of Rubi before we start making changes to the code base.
Note: I previously used the release tag 4.17.2 which was incorrect, the final release from Albert was 4.17.3.