Recently Microsoft had released Office 2010 beta, which can be downloaded for free. You can download the Professional plus version of Office 2010 beta which includes Publisher, Infopath 2010 and also SharePoint Workspace apart from Word, Excel, PowerPoint, Outlook and Access. The installable version is around 700MB in size and to download the version you will need to register with Microsoft. The activation keys are provided after you registration.

Microsoft Office 2010 Beta includes:
1. Microsoft Word
2. Microsoft Excel
3. Microsoft PowerPoint
4. Microsoft Access
5. Microsoft Outlook
6. Microsoft OneNote
7. Microsoft InfoPath
8. Microsoft SharePoint Workspace
9. Microsoft Publisher
10. Microsoft Communicator

The beta keys are valid till October 2010. You will need to activate the keys online within 30 days of installation. By using the following link you can download Office 2010 Beta:

Download Office 2010 Beta