feature-rich and very fast scenegraph-engine. Its purpose is to deliver a toolkit for the creation of interactive 3D environments using the graphic-hardware of common desktop computers.
a 2D graphics library, support for multiple output devices. (output targets include the X Window System, Win32, image buffers, PostScript, PDF, and SVG file output. Experimental backends OpenGL (through glitz), Quartz, and XCB.
The Linux Kernel is one of the most complex open source projects. There are a lot of books, however it is still a difficult subject to comprehend. The Interactive map of Linux Kernel gives you a top-down view of the Kernel. You can see most important layers, functionalities, modules, functions and calls. You can zoom in and drag around to see details. Each item on the map is a hypertext link to source code or documentation.