A public beta version of Windows Server 2016 (then still called "vNext") branded as "Windows Server Technical Preview" was released on October 1, 2014; the technical preview builds are aimed toward enterprise users. The first Technical Preview was first set to expire on April 15, 2015 but Microsoft later released a tool to extend the expiry date, to last until the second tech preview of the OS in May 2015. The second beta version, "Technical Preview 2", was released on May 4, 2015. Third preview version, "Technical Preview 3" was released on August 19, 2015. "Technical Preview 4" was released on November 19, 2015. "Technical Preview 5" was released on April 27, 2016.