Inkscape

Inkscape is a free, open-source graphics program for creating and editing images in a variety of formats suitable for print and web use. Inkscape's features make it similar to Adobe Illustrator, Adobe Photoshop, and CorelDRAW. A variety of free plugins also provide additional functionality.

What Can I Do With Inkscape?
Inkscape is an open-source vector graphics editing program. Unlike bitmap or raster graphics, which are bound to a specific resolution and will become pixelated or distorted if expanded, vector graphics are resolution-independent. Thus, vector graphics can be scaled to any size or zoom level with no degradation in image quality. Vector graphics are also smaller in file size than raster graphics. Inkscape can be used to create images, as well as to edit both vector and raster graphics.

For Designers of all Kinds
The design process may begin by doodles on a napkin, a sketched mindmap, a photo of a memorable object, or a mockup in software which really wouldn't work to complete the project. Inkscape.

Professional Publishing
All Inkscape projects may be exported in formats friendly to web browsers or commercial printer rooms. It is cross-platform, which means it is easy to run on Windows, Mac OS X, and Linux distributions.