BuGLe is a freeware debugger for Linux and other UNIX-like OSes. BuGLe combines a graphical OpenGL debugger with a selection of filters on the OpenGL command stream. The debugger allows viewing of state, textures, framebuffers and shaders, while the filters allow for logging, error checking, video capture and more.
gDEBugger is a full-featured and free debugger and profiler representing the state-of-the-art in OpenGL and OpenGL ES debugging and profiling on Microsoft Windows and Linux.
GLIntercept is a freeware debugger/logger for Microsoft Windows 2000 & XP. GLIntercept can save function calls, textures, shaders, error states, and framebuffer data to XML or text file logs. Logging can be per-frame or continuous. The plugin system provided also allows real-time editing of shaders and manipulation of OpenGL states.
KTX is a lightweight file format for delivering textures to OpenGL family APIs.
Nsight Visual Studio supports OpenGL frame debugging and profiling, GLSL GPU shader debugging and local single GPU shader debugging.