Microsoft has released Office universal apps Word, Excel, and PowerPoint for the Windows 10 Technical Preview. You can download the apps from the Windows Store Beta. The new universal apps are designed to work on every touch enabled device running Windows 10, from a Windows Phone to desktop PC and even on 84-inch Surface Hub. OneNote is already available. Outlook and Calendar are expected to be released very soon.
Screenshots of Office universal apps:
Outlook Mail and Outlook Calendar