Microsoft has given some details about how the Windows Holographic Platform, part of Windows 10. The Holographic Platform is an extension of the Windows 10 development platform, meaning that any developer should be able to build software with holograms in mind.
When wearing HoloLens, you're presented with a holographic Start menu, giving you access to your apps. You can pin an app, like a video player, to a wall, and resize it as large as you'd like. You can use a voice command to have your app follow you around. You can also collaborate with other people wearing HoloLens.
Microsoft has announced NASA's Jet Propulsion Laboratory, AutoDesk, Disney, and more as partners to develop software for HoloLens.