MS Office is popular for a reason. Microsoft and its massive user base have kicked it hard, and polished the roughest edges along the way. The hidden gotcha is that MS now holds your data hostage. Their applications define if your data can be read, and how you can manipulate it. The Gnumeric project began as a way to ensure the GNOME platform could support the requirements of a major application. It has evolved into the core of a spreadsheet platform that we hope will grow past the limitations of MS Excel. Gnumeric has taught us a lot about spreadsheets and, for the purpose of this talk, about what types of capabilities MS has put into its libraries and applications to provide the UI that people are familiar with. I'd like to discuss the tools (available and unwritten) necessary to produce a competitor and eventually a replacement.