silverlining realtime 3D clouds and sky sdk

SilverLining is a software development kit that renders photorealistic real-time skies, including 3D volumetric clouds, precipitation effects, stars and planets, and provides physically realistic outdoor lighting to your application. SilverLining can power games, visual simulation, training, broadcast video, and architectural visualization applications to name a few, and is a platform for Windows, MacOSX, and Linux. Get a free demo, free evaluation SDK, and get information on licensing.