If you are working on a LaTeX successor you could be interested in TeXmacs, which is a LaTeX successor which works very nicely in many ways, except apparently s

If you are working on a LaTeX successor you could be interested in TeXmacs, which is a LaTeX successor which works very nicely in many ways, except apparently selling itself well :-) You could see there how it was designed and how the author answered the questions you are asking.