D2X-XL - (Linux, Windows, Mac) D2X-XL is the most advanced and feature-rich user-enhanced version of Descent to date, as it offers many features like colored lighting, smoke, real-time shadowing, new weapon effects and new game modes that enhance the single-player experience and give new twists to multi-player games. As most ports, it retains full compatibility with the original game and can be switched in appearance between a graphically updated version, and the original look and feel of Descent. When you go to the Web site, make sure you roll your mouse over the side menu to understand the range of levels that can be downloaded. Price: Free.