Microsoft Office 2010
The UI is based on the Ribbon UI carried over from Office 2007, but is now included in the whole suite and now also full native ribbon customization is available (in Office 2007, only the Developer tab could be added/removed natively).
Many Office 2010 versions (especially the beta versions) will fail somewhere towards the end with no reason given for the failure. This is because the time is incorrect. Changing the system time to an appropriate time should work.
Office Starter is the free, albeit ad-included and stripped down version of Word and Excel. This version is found in an Office Click-to-Run (C2R), which allows either a bought version of Office to install, or install this. The file can be downloaded from MajorGeeks, but the C2R functions can only be obtained from OEMs.
Office Home and Student is designed for basic use and school use. It includes Word, Excel, PowerPoint and OneNote.
Office Home and Business is essentially Home and Student, but also contains Outlook. Microsoft intended the version to be for small businesses. It includes Word, Excel, PowerPoint, Outlook, and OneNote.
Office Professional is the high end retail version. It includes Access and Publisher.
Office Professional Plus is the top end version. It includes InfoPath in addition to the versions on Professional. This is meant for businesses only, along with the somewhat reduced Office Standard.