This project assesses the current state of interoperability among different software implementations of the document formats OpenDocument Format (ODF) and Office Open XML (OOXML). Numerous governments are considering mandating either or both formats for their electronic documents. For ODF, the dominant implementation is OpenOffice.org and for OOXML, the dominant implementation is Microsoft Office. This research scores the performance of other alternative implementations for ODF and OOXML. The goal is to assess the current state of interoperability for document formats. The results show that there are no alternative implementations, for either ODF or OOXML, that offer 100% compatibility with the dominant implementations. The results are troubling and suggest the need for improved interoperability testing. Without such testing, governments will be locked-in into the dominant implementations for either standard.