MWEdit is a fan made plugin editor for Morrowind mods. Contact Dave Humphrey (dave@uesp.net) for more information.
It requires the UESP mw-common repository code to compile.
Note that this was written in a very old version of MS Visual C/C++. It has been modified to compile in VS 2015 but may need more work for more modern VS versions.
This is the original v0.6.1 code. There are likely other MWEdit clones derived from this that have additional functionality added to them.