When I try to run apps that require OpenGL, I get this

Video Driver: OpenGL

Initializing OpenGL...
Your system is reporting that direct rendering is not available. Please obtain an updated driver from your video card manufacturer.

This was never an issue with the previous version of Antix that I used. I think I have an Intel Intergrated Graphics card.

Do you have a nvidia card? If so you'll need to install the nvidia drivers via the Mepis/Xconfig app.