I would like to see a bit of work put into the landlord project. I was able to compile it on Linux, though when I tried to load it the GUI appeared to be missing image and text assets so the user interface was pretty unusable. I guess there is some assumption about resources, such as those tilesets, which isn't well documented.
On a side note, I run the Linux command line tool cppcheck over a number of OPU projects, and it picked up a problem in this one.
Checking src/Map/TileSetManager.cpp ...
[src/Map/TileSetManager.cpp:13]: (error) Using 'memset' on struct that contains a 'std::string'.
This seems to result from some old code that I wrote for OP2Editor which got reused here, but with a field type change from char* to std::string.
I was going to open an issue for the above, but it seems there's no issue page on that project link. I assume because it's been forked from elsewhere. I checked the original repository, but it seemed to be far out of date from the forked copy.
Having a C# map editor sounds interesting. Sounds like it may be easier to develop a map editor using C#. I have no idea how to run it on Linux though. It would be kind of interesting to see what might happen if there were 2 competing projects.
A number of the OPU projects on GitHub have been getting ReadMe files added and updated. Hopefully this will make the projects easier to use for people who want to dabble. (It might still be a couple days before the changes are merged in to master. Some of it needs a bit of proofreading and editing).