This is a new incarnation of the old, abandoned version from SourceForge. The original website is still available (at time of writing) at https://xpertmud.sourceforge.net/.
It has been ported to Qt5 and the CMake build system. It can run on Windows, MacOS, and Linux.
Development on Xpertmud can best be described as a "passion project" that came about due to some fond memories of using it back in the day. Support should be considered effectively nonexistent, but pull requests will be considered if you feel compelled to contribute.
A reasonable effort is being made to maintain the build on Linux but with very limited functional testing, so it may break or behave strangely. MacOS is for all practical purposes unsupportable by myself, but existing support will be left as-is and efforts will be made to try not to obviously break anything.
Python is the only scripting language receiving any meaningful attention currently. As with the above, effort will be made to at least make sure Perl and Ruby are not obviously broken.
None. If anything comes to mind it may (or may not) be implemented. Xpertmud was already fairly esoteric among MUD clients even in its heyday, and now it's practically a relic.
A wonderful, beautiful, relic, but a relic nonetheless :)