I can provide some extra infos about MV, RM and RMME.
As Deledrius said, MV uses an engine very similar to Uru's, so converting Ages to Uru is a relatively simple process using Drizzle. It's been quite bugged for a long time, but recently I made adjustments to Drizzle so that Ages are handled better and are playable almost perfectly (that's
Drizzle32). The modified version of these Ages is not on any Shard AFAIK.
As for realMyst. RM uses the same engine as Uru and MV, but the version is so old that it's almost another engine. Drizzle
has a tab somewhere to extract some models from RM, but you will find it's not really useful for anything currently.
The reason for this is the guy behind Drizzle (Dustin) managed to get Drizzle to read and fully understand RM Ages, and was working on an automatic conversion from RM to Uru - just like what we have for MV. However, he left the community a while ago due to personal grudges and his bad temper (long story short). He did make the Drizzle source code available, but didn't include most of his work on RM.
While I was fixing the MV conversion in Drizzle32, I did try to also fix the RM conversion, but found out that the code available isn't very useful, because it's unable to read most of the RM data. Converting existing data from one game engine to Uru isn't very difficult - but reverse-engineering the realMyst executable to know what to read is insanely hard. So we're kind of stuck on this end.
(the most you can get out of Drizzle can be seen
here,
here and
here. It's not realMyst, it's realMess)
Now, about RMME... As you know, RMME was made with Unity. And once exported, Unity games are compiled and tighly packed in order to make reverse-engineering crazy hard.
Assets are stored in the sharedassetsX.assets, but you'll find out that there are very few tool to open these files, and most of the time they don't output anything useful.
Unity's scripting engine might be it's weakest point for extracting data (since all script are stored into a convenient DLL), but so far I've failed to modify it with existing tools.
And to finish... Rebuilding these Ages. That might be a safer bet, since it would avoid most copyright issues, allowing to distribute it freely and put it on any Shard you might want. Plus, you'd be able to upgrade the visuals if needed.
But of course, it's still a tremendous amount of efforts. Also, you'll have a bad time getting the correct dimensions because most realMyst Ages are structurally impossible.
As for whether it's worth it... Well, that depends on how much you are willing to put in it.
- Show Spoiler
http://s1156.photobucket.com/user/J_rius/library/Mechanical?sort=6&page=1
To be honest, I grow tired of the idleness of Uru nowadays.
Currently I'm more excited about VR and how it will change gameplay than rebuilding Ages I already know by heart.