The OGB (not to be confused with ODB) recently had a post about Document Freedom. This is an issue I feel more passionately than articulate about. I'll do my best here to convey why I think it's important, expecting to lose most of you before the fourth paragraph.
For a long time now, a huge chunk of the world has used Microsoft Office. That works fine, short term. But in the long run, it can be risky.
When Microsoft puts out a new version of its software, it subtly changes the way the software reads the files and makes them into documents. This is a great way to keep the documents in line with current technology, and a great way to keep you updating your software. It wasn't too long ago I was collaborating with some fellow law students, when someone contributed a .docx file. None of us could read the damn thing. This is a great way to get us to either all buy Office 2007 (or yell at the person for using a bizarre format).
There's another side effect of this planned obsolescence. Enough revisions down the line, Microsoft could stop programming Microsoft Word to read Microsoft Word 1995 documents (and either stop making a Word 1995 reader for Windows 2012, or charge corporate customer prices for it).
(This sounds like a far fetched possibility, but Microsoft's Windows Media Player underwent some dramatic feature losses as it went from version 5.1 to 9.)
What happens when Microsoft outgrows its old formats? Your vital records you've been foolishly storing on a dusty floppy in your basement are lost forever. A brilliant inventor's early designs, gone. Historical or geneological records, no more. Government documents relevant for determining key ownership issues, vanished.
Open Document standards fight against these scenarios. Open Document Standards turn machine gibberish into text documents in ways that everyone can poke at and copy into their own programs, there are no hidden proprietary tricks.
Two years back, Massachusetts drew a little more attention to this issue when they began demanding all state documents be produced in open formats. Perhaps they were anticipating the lesson Hoboken, NJ learned a year later, don't leave vital public functions in the hands of a corporation (Hoboken learned this when a robotic parking garage licensed by the city refused to let anyone access their cars until the state paid the company its fee).
Fortunately, Microsoft has started bowing to the Open Document pressure, supporting the Open Document format, and (sort of)* opening their proprietary formats.
*(Is a promise not to sue the same thing as openness?)
Better still, there are plenty of other open format based options available for the general public. Some of these alternative word processors are free and high quality (arguably better than Microsoft products, especially for certain key uses). OpenOffice.org and Google Docs come to mind, but there are several others.