Inkscape - Open source SVG graphics editor released under the GPL. Official site includes download links, documentation, and resources for the developer and user communities.

A Guide to Inkscape - Online book describes features and tools, giving examples of their use.

Inkscape LaTEX Extension - An extension to enable a combined export format with text in a LaTeX picture environment and everything else as EPS. Background information, screenshots, download, and release history.

TexText - Inkscape extension to add editable LaTeX text objects to a document. Includes overview and download.

Wikipedia: Inkscape - Article gives an overview of features and history.