Today, March 31st, is Document Freedom Day. It's a day in which we (for some fuzzy meaning of "we", but including at least Free Software developers) stress the importance of Open document formats. Those are formats which are documented as an Open Standard, which is to say that their syntax and semantics are both described in a fashion that is available to the public and well understood. Plain text is such a format, and it works well for certain kinds of unstructured documents -- stories, essays, etc. Well, assuming you know what character encoding is used and that the hardware encoding is understood as well. If you want a little more structure, then something like LaTeX can get you markup and layout and whatnot. However, LaTeX can be a terrible mess and understanding just what a given document does can't really be decided except by running LaTeX over it and waiting for output.
A really Open document format has a standards document attached to it, one that defines exactly what the syntax and semantics are. Preferably a standards document that is controlled by a trustworthy standards body -- one in which procedures are documented and followed and where the public interest is served. That way, you end up with a document standard that is stable, well-defined and useful.
In theory, anyway.
So of course this is all hinting at ODF (OpenDocument Format), which has a specification (v.1.1) and a process for updating the specification when needed. I believe the specification itself has its issues --- it really is difficult to specify syntax and semantics with rigor --- but it gets the job done and, most importantly, is written in good faith and available for everyone to implement on a royalty-free basis. The latter is important because we want to play by the rules but also need to enable current and future implementations of tools that use the document format without restrictions.
Document Freedom Day focuses on ODF, but it's about all Open document formats. And about implementations --- for ODF, we have OpenOffice.org and KOffice and the GNOME office tools. There are also command-line tools and applications that process ODF files without being WYSIWYG editors. Or consider OfficeShots, the side-by-side comparison tool for ODF applications. Again something that is enabled by royalty-free use of the standard.
As I've been writing this, Document Freedom Day celebrations have been kicking off in various places -- for instance, in Baarn, not 80km from where I live (but I'm in no state to travel there) or Slovenia.