I've never seen ascimath before but I wish I had because I think I partially reinvented the wheel. I wrote some extensions to Pandoc (and an associated emacs major-mode) for scientific note-taking, with a main portion being a "simplified latex" for writing equations in a more readable way. The key features of simplified latex format are matlab-style matrices, UTF8 support, easy exponents, and better formatting (e.g. functions automatically use roman instead of italics). There are still a few edge cases mine doesn't catch, but I'm in the process of rewriting it in Haskell and rewrite is more stable.
https://code.launchpad.net/~mwshinn/+junk/notes3
or for documentation:
https://bazaar.launchpad.net/~mwshinn/+junk/notes3/view/head...
Open/LibreOffice math formulas use a syntax that's clearly inspired by it. Unfortunately it's very lacking in documentation.
Another important question is are you looking for presentational or semantic math? For presentational fine tuning I'm afraid nothing can beat the flexibility of TeX combined with a huge body of Q&A (on stack exchange and elsewhere)...