Optifine

This mod adds support for HD textures and a lot of options for better looks and performance. Doubling the FPS is common.

- Features :  
    FPS boost (examples)
    Support for HD Textures
    Variable Render Distance
    Configurable Smooth Lighting (examples)
    Performance: VSync
    Synchronizes framerate with monitor refresh rate to remove split frames and smooth gameplay
    Smart Advanced OpenGL
    Fog control
    And More Features.

For More Information and Download check link : http://www.minecraftforum.net/topic/249637-132-optifine-hd-b3-fps-boost-hd-textures-aa-af-and-much-more/