Minecraft is a pretty graphically intense game for just being a bunch of blocks. But hopefully that will change in the future - but drop compatibility for some older machines in the process. Today Mojang posted a support article explaining, "In the far future (at least past Minecraft version 1.8, if not later), Minecraft will no longer support OpenGL versions older than 2.1."For clarification, OpenGL is a technology used by countless graphics cards to render 2D and 3D graphics. OpenGL is used by a wide variety of computer programs, ranging from modeling software to video games. OpenGL 2.1 was released in 2006 and graphics cards supporting it started to be released shortly after that. OpenGL 2.1 isn't too different from OpenGL 2.0, the major difference is improving the performance of certain image transfers.
But how can you tell if your graphics card has OpenGL 2.1 support? Mojang writes, "If your version of OpenGL is too old, and you're running snapshot version 13w38b, or a release version newer than 1.6.4, you will see the following title screen [seen above]."
If you get the message, don't panic. It's possible your graphics card may support OpenGL 2.1, but it may need proper drivers to utilize it. If you recieve the above message, we recommend making a visit to your graphics card's manufacturer's website and downloading the newest drivers for your system. See the full story in the link below.
Source: Mojang