Last year Microsoft said that they would publish the format specifications for personal store files (pst) – formats used to store data from Outlook products, including email, contacts and diary appointments. You can find them at MSDN here: http://msdn.microsoft.com/en-us/library/ff387869.aspx. There is also format information for other Office products: http://msdn.microsoft.com/en-us/library/cc313118.aspx.
Related sites of interest include Microsoft’s interoperability pages, such as their ‘open specification promise‘ and Microsoft’s interoperability blog.
This is the stated mission of a Google engineering team called the ‘Data Liberation Front’:
Users should be able to control the data they store in any of Google’s products. Our team’s goal is to make it easier to move data in and out
Yay! Loyalty is best achieved through great products, not data lock-in. As an individual who uses online data services this approach makes me very happy. As an archivist I’m ecstatic. Thanks guys.
More about how to get data in and out of Google’s many services at the DLF’s blog.