Minimal OpenGL Utility Library (MOGUL) is a library similar to GLUT, only with fewer features. It lets you write window-system-independent OpenGL programs with even fewer lines of code than GLUT. It currently supports X11 and Win32. Examples are included in the distribution. It is intended to be easy to learn and simple to use.
The Ecere SDK is a cross-platform toolkit for building software applications. It currently runs on Windows, Linux, Mac OS X (through X11), FreeBSD, and the Android OS. It should run on other Unix platforms with minor testing/tweaking. With the Ecere SDK, you can develop applications once and deploy them on all supported platforms alongside a lightweight runtime environment. It introduces eC, an object oriented language derived from and fully compatible with C, compromising neither runtime performance nor ease of use. A built-in 3D engine supporting both Direct3D and OpenGL is fully integrated.
Vis/Space is a client-server system for visually exploring data structures in 3D virtual space. It allows the placement of various data sources in a three-dimensional environment. Custom search terms can be entered into a query field, or can be navigated to and from an existing object. All objects like images and "text screens" can be moved around. A single click on an image shows the full-resolution version in the foreground. Whole collections of images can be moved. A click to the cube also toggles among several different possible layouts. Data sources include search engines, microblogging, Wikipedia, image/video search, and 4chan.