Microsoft is preparing to name its "Windows Blue" upgrade as Windows 8.1. ZDNet's Mary Jo Foley first unveiled the name, but The Verge has confirmed with its own sources that Microsoft will name Windows 8.1 as the upgrade to Windows 8. The upgrade will include a number of improvements to the operating system that are not usually distributed in Service Packs. Windows 8.1 will mark a new approach to Windows upgrades and updates, bringing future version changes on a yearly basis.

Microsoft will release its first Windows 8.1 public preview at its Build developer conference in late June. The software maker opened up registration for the conference today, and tickets are expected to sell out fast. Windows 8.1 will be part of the agenda, but Microsoft is also expected to detail further changes across its software and services at Build. Xbox, Windows Phone, and Windows Server are also slated to be part of Build 2013.