Is there any justifiable reason why Microsoft changes their document formats with every new version of MS Office? For example, I have an older version of Office on my work computer than some other people. In order for me to open documents or spreadsheets that they've created I had to get some converter. Is there any real justification for this other than it is an asshole way for them to pressure people to upgrade? It is shit like this that really annoys me with Microsoft. By the way, I'm sure other companies do it as well, but MS is the one who seems to be the worst offender to me.