Apple discontinued the use of PowerPC microprocessors in 2006. At WWDC 2005, Steve Jobs announced this transition, revealing that Mac OS X was always developed to run on both the Intel and PowerPC architectures. All new Macs now use x86 processors made by Intel, and some were renamed as a result. Intel-based Macs running OS X 10.6 and below (support has been discontinued since 10.7) can run pre-existing software developed for PowerPC using an emulator called Rosetta, although at noticeably slower speeds than native programs. However, the Classic environment is unavailable on the Intel architecture. Intel chips introduced the potential to run the Microsoft Windows operating system natively on Apple hardware, without emulation software such as Virtual PC. In March 2006, a group of hackers announced that they were able to run Windows XP on an Intel-based Mac. The group released their software as open source and has posted it for download on their website. On April 5, 2006, Apple announced the availability of the public beta of Boot Camp, software that allows owners of Intel-based Macs to install Windows XP on their machines; later versions added support for Windows Vista and Windows 7. Classic was discontinued in Mac OS X 10.5, and Boot Camp became a standard feature on Intel-based Macs.

When did Apple discontinue the use of PowerPC microprocessors?