[nness]

Not to mention the fundamental differences between pre-2007 and Office 2007 document formats. I tend to think that the format change wasn't a forced deprecation of older software, but rather just a simple business case. Simplify maintenance and support, and create an open-ish standard to avoid competition + support industry.

[Aloha]

the old binary formats for office were the collected history of 20 years of software development, and even Microsoft had trouble with consistent implementation - at least OOXML had a digestible easy to use standard.