Writing Mathematics on the Internet. Witing equations is difficult in a doc, they have to be font independent, that implies images. Webapps do it well.

LyX combines the power and flexibility of TeX/LaTeX with the ease of use of a graphical interface. This results in world-class support for creation of mathematical content (via a fully integrated equation editor) and structured documents like academic articles, theses, and books.

Also try AbiWord a free word processing program. Excellent for a wide variety of word processing tasks. Has MathML and LaTex input.

- OpenOffice.org is an open source office suite and has an equation editor which can export formulas in MathML
- GtkMathView is a C++ rendering engine for MathML documents.
- MathML Software – Editors

LaTeX Equation Editor -Equation Maths

The interactive LaTex equation editor let’s you write and download equations in seconds! You can now integrate the sitmo equation editor with iGoogle or your own site. – sitmo