LuxMax is now the new integrated renderer for 3dsMax, it's being fully integrated just like any other production renderer.
It's being developed using the LuxCore library, and everything is implemented using c++.
At the moment it's being actively developed, new features are added all the time.
It's still early in development, so it's not feature complete, but the wiki is being updated each time a new features is added.
You find the wiki here: http://www.luxrender.net/wiki/Luxmax_integrated
You can grab LuxMax latest release from the repository where all latest changes are commited: https://bitbucket.org/luxrender/luxmax
In order to make LuxMax better we highly encourage you to try it and report your suggestions/issues in the 3dsmax subforum:http://www.luxrender.net/forum/viewforum.php?f=33
Or report them in the bugtracker:http://www.luxrender.net/mantis