Programmable shading. With the new release, both OpenGL Shading Language and its APIs are now core features of OpenGL. New functionality includes the ability to create shader and program objects; and the ability to write vertex and fragment shaders in OpenGL Shading Language.
Multiple render targets that enable programmable shaders to write different values to multiple output buffers in a single pass.
Non-power-of-two textures for all texture targets, thereby supporting rectangular textures and reducing memory consumption.
Two-sided stencil, with the ability to define stencil functionality for the front and back faces of primitives, improving performance of shadow volume and constructive solid geometry rendering algorithms.
Point sprites, which replace point texture coordinates with texture coordinates interpolated across the point. This allows drawing points as customized textures, useful for particle systems.