from the Muon1 Forum
The presence of "1" in the name of Muon1 has confused a few people who think it's part of the version number (currently Muon1 v4.45). In fact, it got called that because it was the first muon-related program I wrote, allowing Muon2, Muon3 etc. to be entirely different programs doing other calculations related to muons.
This system only got as far as "Muon2", a program from 2001 that I still have. It displays particle tracks as curves instead of a cloud of particles and allows the input position to be interactively varied. Its main use was to find the correct paths through the bending magnet fieldmaps used in the "Chicane" lattices early in the project .
Soon it became clear that this project shared so much common code (the particle stepping, fieldmap and plotting) with Muon1 that maintaining a separate program was wasteful. Instead, I can now compile auxiliary 'testing' modules into Muon1 to display persistent particle trajectories if needed.
All the above by Stephen