Facing the threat of shutout from government bids, Microsoft is opening up the file formats for Office 2003. This is a big step, because it means that other software products that want to be able to make use of Office files will be able to do so with far greater compatibility than in the past. Open source projects like Abiword, Gnumeric and Open Office will really gain from this. And, Microsoft even designed the license to ensure that open products can make use of the formats, even if a Microsoft patent covers the use of the format. Good deal!
People paying close attention did notice that there is an attribution clause in the license (which means that you have to credit Microsoft for the file format package if you use it). This is not compatible with the GPL license, which means that GPL’ed software will likely need to do some tricks like having a plugin for the MS office formats. We’ll see how people deal with that.