Just this February Intel released the Katmai New Instruction set along with their new Pentium III processor to compete with their competitor AMD. Back in May of 98 AMD released the first innovative leading edge technology to enhance 3D multimedia.
This technology, called 3DNOW!, was AMD's answer to the lack of sales with the AMD K5 and AMD K6 processors. While the K6 successfully captured the lowed business market, the rest of the market turned to the all-mighty Intel Pentium. The reason for this was not only because the Pentium slightly outperformed the K6 in standard business applications such as Microsoft Office, etc., but because the Pentium had raw FPU power. Back in the day when Doom used to be the ultimate game, you would see the screen stutter on a K5 and on some K6 processors. While on the Pentium processor the game would run so smooth that it felt like you were playing it on a console. Keep in mind that Doom ran all software until recently when it was released for OpenGL.
The K6-2 3DNOW! drastically increased multimedia and gaming performance. The largest improvement to the processor was it new improved FPU. This improved performance in most games (especially 3D games), multimedia software, and some productivity software. You would especially notice the improvement in floating point intensive applications such as CAD software and Mp3 players.
The new 3DNOW! instruction set took a little more time to become implemented. The reason for this was because software must be optimized to recognize and take advantage of the 21 new instructions implemented within the x86 architecture. But after time AMD was able to get Microsoft to optimize it's fairly new API called DirectX 6. Silicon Graphics later followed by optimizing OpenGL for 3dNOW!. This covers a lot of the 3d gaming market. It can also increase the speed of decoding mpeg videos. Currently you may find plenty of titles optimized for 3DNOW!. A list of optimized products can be be viewed at http://www.amd.com/products/cpg/k623d/optimized.html.
Intel's Katmai New Instructions (KNI) implementation is a newly created set of x86 multimedia instructions debuting as a feature of Intel's Pentium III processor.