HostMath - A powerful interactive mathematical expressions editor

  HostMath is a powerful interactive mathematical expressions editor. It
uses WYSIWYG-style editing and allows creating mathematical equations
through simple point-and-click techniques.

1. Many pre-defined Templates and Symbols in well-organized palettes
that cover Mathematics, Physics, Electronics, and many other higher
educations
2. Fine adjustment for Template shapes, gaps, and thicknesses with
visual interface
3. Multiple Undo and Redo
4. Can generate equations as MathML. MathML will allow you to copy and
paste math into many applications that understand MathML.

URL: http://www.hostmath.com/