Emacs minor mode and a shell-script deamon for incrementally previewing TeX files using either ghostscript-based or dvi-based previewers. Download and documentation.
Overview of a package providing some semi-WYSIWYG in LaTeX or HTML source. Beyond that there are a description of the details, a manual and links to the project pages on sourceforge.
Downloads and documentation of a graphical user interface front-end for the computer algebra system Maxima. Imaxima processes the output from Maxima with LaTeX to render the mathematical formula.