Android (operating system) top-selling platform in April 2011, overtaking BlackBerry OS with a 31.2% smartphone share, according to "comScore". By the third quarter of 2011, Gartner estimated that more than half (52.5%) of the smartphone sales belonged to Android. By the third quarter of 2012 Android had a 75% share of the global smartphone market according to the research firm IDC. In July 2011, Google said that 550,000 Android devices were being activated every day, up from 400,000 per day in May, and more than 100 million devices had been activated<ref name="i/o 2011 stats"></ref> with 4.4% growth per week. In September 2012, 500
Operating system However, Windows' usage on servers is not as widespread as on personal computers as Windows competes against Linux and BSD for server market share. ReactOS is a Windows-alternative operating system, which is being developed on the principles of Windows without using any of Microsoft's code. There have been many operating systems that were significant in their day but are no longer so, such as AmigaOS; OS/2 from IBM and Microsoft; classic Mac OS, the non-Unix precursor to Apple's macOS; BeOS; XTS-300; RISC OS; MorphOS; Haiku; BareMetal and FreeMint. Some are still used in niche markets and continue to be developed