As slow as a mountain turning to sand the online version of Myst is going open source. A step forward was taken when Cyan Worlds, Inc., the creators of the Myst series of games, placed the game back online in February, 2010. See: Play Myst Online (Free)
Another step was taken when Cyan released the binary version of their Plasma plug-in for 3DMax (versions 7 only). This allows fans to mod the game. Well to a point, there are complications both technical and license-wise. Those things are to be resolved somewhere along the road to open source.
In the mean time fans are churning out tutorials on how to use 3DMax and the plug-in. Fans expect the plug-in code to be released soon.
“Soon…” there is a whole insiders-fan-good-natured-thing about how to translate Cyan terms related to time into something meaningful to the rest of us. In general terms one could think soon means this year… possibly…
A complete and I think the best set of video tutorials are being made by, The Magician. Here is the link to the: Uru Modding Video Tutorials
On another fan site (GoMa – Guild of Maintainers) Andy is writing text and image tutorials for the fans moving from Blender and PyPRP, previously and currently used to build Uru mods, to 3DMax and Cyan’s Plasma Plug-in. There are both Blender and 3DMax tutorials for Uru modding at: Uru Age Creation Tutorials
Another fan site is providing fans project, forum, wiki, and blog space for Myst-Uru Style builds, OpenUru.org. Fans participating there are working on creating a hosting system to support open source Uru, thus the Open Uru name, supporting fans using Blender, supporting fans working on community issues (forum and game etiquette in Uru’s rather odd mix of IC and OOC play), and Myst-Uru Style builds in OpenSim grids and Second Life. Open Uru.org