Among the technology crowd, one of Apple's most heralded moves was to open its entire operating system to the public, available as source code. The power of OS X's UNIX core was as open as Linux, previously Microsoft's only legitimate competitor. However, Apple has ceased to open the source for the Intel edition of OS X, likely as a means of halting the less talented hackers from porting the code from Apple's line of hardware. The PowerPC (G3, G4 and G5) versions of OS X remain open source to the public. While home users will not be concerned by this move, limiting the distribution of source rankles users with more specific needs - scientists or server administrators that tweak the core to run optimally for their applications.