Microsoft has unveiled its latest OS, Windows 10, which will be offered as a free upgrade to users of Windows 7, 8 and 8.1.

Windows 10 promises to be truly cross-platform, running on everything from smartphones to smart TVs, and even the Xbox One. This is far from the end of Microsofts cross-platform ambitions, it seems.

Microsofts VP of Operating Systems Terry Myerson added: “Stay tuned as our device family expands,” a statement which was quickly followed up with the announcement of two new devices. The first, Microsoft Surface Hub, is a 84” digital whiteboard which seems aimed more towards the enterprise market than consumers.

More interesting is the Microsoft HoloLens, an AR headset which can project holograms onto the users vision. The headset is wireless, and doesnt require tethering to a mobile or desktop device, and comes with an accompanying software suite, Windows Holographic.

Another unifying factor to Microsofts announcements was the personal assistant software Cortana, the companys answer to Apples Siri. Cortana will be brought to desktop for the first time, and is being integrated into most Microsoft services, including Spartan, Microsofts first new web browser since Internet Explorer was launched in 1995.