SciWriter
Science, Math, Software, Typesetting - SciWriter. An XML based WYSIWYG word processor for mathematics and text.
http://www.soft4science.com/
Applied Symbols
Science, Math, Software, Typesetting - Applied Symbols. This company specializes in OpenType fonts for technical and mathematical publications.
https://www.appliedsymbols.com/
OpenMath
Science, Math, Software, Typesetting - OpenMath. Emerging standard for representing mathematical objects semantically, allowing them to be stored in databases and communicated over the World-Wide-Web.
https://openmath.org/