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.
LXRandR is the standard screen manager of LXDE. It manages screen resolution and external monitors. You can plug in another screen into LXDE or choose to use a big screen projector. Local screen and extenal screen can be used at the same time.
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.