The current (as of 2007) entry-level 2D graphics card for Sun workstations. It is a 32-bit/66MHz PCI card, based on an ATI Radeon 7000 chipset. In fact, the card is nearly identical to the Radeon 7000 Mac Edition, except for the contents of its flash EEPROM. The Mac Edition uses Apple Fcode while the XVR-100 uses Sun Fcode. By re-flashing, it's possible to turn one into the other! This is not officially supported by Sun, ATI or Apple, of course.
Curiously, although the Radeon 7000 is capable of hardware-accelerated 3D, the Solaris drivers for the XVR-100 don't expose this functionality. The reason why is unclear, but may have to do with the fact that the Radeon 7000 was designed as a gaming chipset, and so places a premium on speed rather than accuracy in 3D rendering - a problem that could make the card a liability rather than an asset in Sun's typical markets. Also, like most gaming chipsets, it's optimized to render into a single window rather than multiple windows, as most workstation cards are. If you're running Linux, however, it's possible to use the 3D features via the DRI facilities, but it takes some jiggery-pokery to convince Linux and X that it really is a standard Radeon 7000.