JimBaker, the thought of attempting a port of Purple Pen to Mac occurred to me, too, but I never got past the thought stage. I had noticed that PP is described on its web site as being open source
, but just now, when I poked around further, I could find no reference on said site about how to obtain the source. (Keep in mind that I am notorious for overlooking things right under my nose, so maybe it's in there somewhere.)
But a little Google'ing just now turned up a Purple Pen source depository at GitHub
. (And turned up apparently obsolete depositories at SourceForge and LaunchPad). So nothing stopping you or me or anyone else at having a crack at a Mac port.
On this very forum a while back, the developer told us
that he his little to no interest himself in porting PP to Mac. He did express some interest in a phone port.
As you noted, Open Orienteering Mapper has next to no capability for course setting. I saw somewhere a while back a comment from the developers (can't remember where) that adding these capabilities to OOM is of little to no interest to them precisely because PP fills the niche of open source software for course setting. No mention was made of filling that niche on the Mac side.