Glxinfo is described as 'glxinfo is a command-line tool that can help you diagnose problems with your 3D acceleration setup. It can also provide additional helpful information for developers' and is an app in the OS & Utilities category. There are eight alternatives to Glxinfo for Linux and Windows. The best alternative is WattmanGTK, which is both free and Open Source. Other great apps like Glxinfo are hwinfo (Free, Open Source), cpuid (Free, Open Source), vbetool (Free, Open Source) and read-edid (Free, Open Source).
read-edid is a pair of tools (originally by John Fremlin) for reading the EDID from a monitor. It should work with most monitors made since 1996 (except for newer ones with 256-byte EDID's - WiP), assuming the video card supports the standard read commands (most do).
DRIconf is a configuration applet for the Direct Rendering Infrastructure. It allows customizing performance and visual quality settings of OpenGL drivers on a per-driver, per-screen and/or per-application level.