Back in December 2006, Andrew Shebanow commented on the difficulty of creating a converter for Microsoft’s Office 2007 document format, which uses XML after Bob Sutor of IBM called it a one-way format due to its complexity. Based on some numbers posted a Microsoft explaining why it would take longer to release a converter for the Mac version of Office, Shebanow came up with this estimate of the effort required to build such a converter:

It would take 5 developers a year to do a quarter of the work. That means the whole job is roughly 20 man-years of development time. That doesn’t include testing, documentation, or localization. That would probably double the number of man-years, at least. But it gets worse:

This is just for Word. We need additional teams for Excel and PowerPoint.

Back of the envelope, we’re now talking about 120 man-years. For Mac Office, Microsoft decided such an investment wasn’t practical, so instead they waited for Win32 Office to go final and are now porting the Win32 code to the Mac.

Today I read that Microsoft still hasn’t released the converter from Office 2007 to Mac Office 2004. It was scheduled for release in January, but has been pushed back to June.