Xenix was a version of the Unix operating system that Microsoft worked on; in 1982 they engaged with the Santa Cruz Operation (SCO) in this work, with the two companies' engineers working together on improvements. Microsoft and SCO then further engaged Human Computing Resources in Canada, and the Software Products Group within Logica in the United Kingdom, as part of making further improvements to Xenix and porting Xenix to other platforms. In doing so, Microsoft gave HCR and Logica the rights to do Xenix ports and license Xenix binaries in those territories, which for Logica included all of Europe. This second source agreement was formalised between Microsoft and Logica in January 1983.