Because I had no idea what it was:<p><pre><code> Gallium3D is a software library for 3D graphics device drivers being
developed by VMware, after they acquired Tungsten Graphics[1]—the original
authors.
The Gallium3D library operates as a layer between the graphics API and the
operating system with the primary goal of making driver development easier,
bundling otherwise duplicated code of several different drivers at a single
point (this is done by providing a better division of labor, for example,
leaving memory management to the kernel DRI driver) and to support modern
hardware architectures.
Gallium3D is currently used by the free and open source nouveau graphics
driver.
</code></pre>
<a href="http://en.wikipedia.org/wiki/Gallium3D" rel="nofollow">http://en.wikipedia.org/wiki/Gallium3D</a>