Macs, the iMac and the MacBook Pro. These machines used Extensible Firmware Interface (EFI) platform firmware instead of the older style BIOS found on most x86 motherboards at the time. On February 14, 2006, an initial "hack" of v10.4.4 was released on the Internet by a programmer with the pseudonym crg92. Within hours Apple released the 10.4.5 update, which was then hacked by the same author within two weeks. On April 3, 2006, Apple released their 10.4.6 update and again patches were released within two weeks that allowed users to install most of this update on non-Apple computers, although this did not include the updated kernel in 10.4.6. In June 2006, an updated MacBook Pro was released for the 10.4.7 update for non-Apple computers using the 10.4.4 kernel. Up to the release of the 10.4.8 update, all OSx86 patches used the 10.4.4 kernel with the rest of the operating system at version 10.4.8. However, the newer frameworks relied on the newer kernels and this led to users of 10.4.8 encountering many problems. Apple also started making more use of SSE3 instructions on their hardware making it even more difficult for users with CPUs supporting only SSE2 (such as older Pentium 4s) to get a fully compatible system running. To solve this problem, hackers from the community released kernels where those instructions were emulated with SSE2 equivalents, although this produced a performance penalty. Throughout the years, many "distros" were released for download over the Internet. These distros were copies of the Mac OS X installer disc modified to include additional components necessary to make the OS run on the non-Apple hardware. A prominent member of the community, JaS, released many distros of Mac OS X Tiger containing patched kernels. Some other popular distros are iATKOS, Kalyway, iPC and iDeneb. Distros have fallen out of favour as the OSx86 community grew, as new bootloaders were developed that made it possible to use actual copies of the OS X Installer. Mac OS X Leopard (10.5) As early as v10.5 build 9A466 the community has maintained a version of Leopard that can run on non-Apple hardware. A hacker by the handle of BrazilMac created one of the earliest patching processes that made it convenient for users to install onto 3rd party hardware by using a legally obtained, retail version of Apple . This simplification made the BrazilMac patch and its later revisions quickly the