Do you remember the MLAA (Morphological Anti-Aliasing)? In short, MLAA is a shape-based anti-aliasing method that uses post processing filters to reduce aliasing. Like the SSAO, MLAA can be hand-coded in a 3D app or added in graphics drivers.
During the next I3D 2011, NVIDIA will talk about Subpixel Reconstruction Anti-Aliasing or SRAA, a potential competitor of AMD’s MLAA:
Subpixel Reconstruction Antialiasing (SRAA) combines single-pixel (1x) shading with subpixel visibility to create antialiased images without increasing the shading cost. SRAA targets deferred-shading renderers, which cannot use multisample antialiasing. SRAA operates as a post-process on a rendered image with superresolution depth and normal buffers, so it can be incorporated into an existing renderer without modifying the shaders. In this way SRAA resembles Morphological Antialiasing (MLAA), but the new algorithm can better respect geometric boundaries and has fixed runtime independent of scene and image complexity. SRAA benefits shading-bound applications. For example, our implementation evaluates SRAA in 1.8 ms (1280×720) to yield antialiasing quality comparable to 4-16x shading. Thus SRAA would produce a net speedup over supersampling for applications that spend 1 ms or more on shading; for comparison, most modern games spend 5-10 ms shading. We also describe simplifications that increase performance by reducing quality.
Offical page @ NVIDIA: Subpixel Reconstruction Antialiasing.