OOXML and ODF, Technical Comparisons
The Microsoft-sponsored ODF Converter project is implementing workarounds for problems that are mostly caused by technical deficiencies in OOXML. For example, the format is not as extensible as it should be. And you thought XML was supposed to be eXtensible Markup Language. 🙂
Fortunately, both formats are based on XML, so it should be a fairly simple XSL transform to convert from one format to another. Unfortunately, some things do not translate, or do not translate well.
The ODF standard reuses proven standards, such as SVG, XLink, and MathML. There is a technical comparison available, showing why ODF works better. Looking at the two sets of formats, one has to wonder why anyone would use a different format. ODF wins on every comparison.