SkyOS is a discontinued prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. Its first version was released in 1997, and its last beta build was released in 2008.
As of January 2009, development of the OS has been halted, with no plans to resume its development.
In August 2013, developer Robert Szeleney announced the release of a public beta on the SkyOS website. This allows public users to download a Live CD of the SkyOS operating system, for testing and to optionally install the system.
History
thumb|A very early version of SkyOS
thumb|Another early version of SkyOS
Development started in 1996, with the first version released in December 1997.
Up until version 4.x, the OS was freely available. Starting with beta development of SkyOS 5 in 2003, users were required to pay US$30 to get access to beta releases.
SkyOS adapted new filesystem SkyFS based on OpenBFS in 2004, and its graphics subsystem was improved in 2006 with support for desktop compositing, including double buffering and transparency. The OS also moved to ELF binaries then.
The last beta build 6947 was released in August 2008,
As the OS was mainly the work of one man, Robert Szeleney, there was increasing difficulty to add new device drivers. and reported some progress in this regard, development has not resumed.
SkyOS website disappeared in 2013 and final public build from August 2008 was released for free shortly thereafter. GIMP and AbiWord.