Some of the most popular changes to Office 2010 are online.

There are three editions of cheap microsoft software listed in the online shop: Office Professional, costing $499.99; Office Home and Business, which omits the Publisher and Access programs and is costing $279.99; and Office Home and Student, which omits Publisher, Access and Outlook and it is costing $149.99.

No big Microsoft release is finished without an "official launch event," so the head from the company's Business Division, Stephen Elop, will host a celebration on May 12 that'll be broadcast from "the largest studio on the planet: NBC Studios in New York City," Microsoft said.

RTM is a big day for that buy office 2010 professional engineers who've been slogging off to get the software out of the door. It is also a large day for Microsoft, which still gets a hefty chunk of its profits from Office, even as low-cost, Web-based alternatives from Google, Zoho yet others gain in popularity.

Microsoft thanked the "more than 5,000 organizations and partners" who helped test the 2010 products. It said 7.5 million individuals have downloaded the beta of Office 2010 since its release in November, 3 times the number who downloaded the windows 8.1 enterprise beta.