Draw SVG Online Inkscape alternative, useful to edit SVG files.
Inkscape Free and open-source vector graphics editor; it can create or edit vector graphics such as illustrations, diagrams, line arts, charts, logos and complex paintings.
LateXit! Small utility that allows you to quickly typeset LaTeX equations, without bothering with file creation, preambles, and so on. The PDF image obtained can then be exported by drag'n drop to any application supporting it.
Detextify Just draw the symbol you are looking for and get the latex code.