meson.build code analysis
Meson is not a typical programming language but it could still be helpful to have smart code analysis for it when editing the meson.build file. Currently I don't think there are tools for the required features so they will need to be developed, probably using meson as a python library.
I think features that could help for Meson are:
Auto completion - I'm not sure how useful it is, maybe word completion with a pre defined words would be enough.
Linting - this is the most important in my opinion, it would be helpful to see errors while you edit the file. I think it could also be easy to start with running the Parser (mparser.py) and showing any syntax errors.
Documentation - great way to understand the meson.build file that Builder is creating.