(Open Source UNIX) The Unix variants that are maintained as open source, which were primarily BSD Unix and Linux until Sun made its Solaris operating system open source in 2005. See Unix.
"OSU." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/osu>.
OSU. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/osu