Usage share of operating systems computer's installed base statistics, and actual (web) use needs not follow installed base. Also, Microsoft includes tablets (but StatCounter may also for Windows, while it wouldn't for e.g. Android). Video game store Steam publishes a monthly "Hardware & Software Survey", with the statistics below: By Q1 2018, mobile operating systems that can be found on smartphones, include Google's dominant Android (and variants) and Apple's iOS, with both combined at almost 100% market share. According to research by InsightPortal, there is a clear correlation between the GDP per capita of a country and that country's respective smartphone OS market share, Showing
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