In praise of Open Standards

I am working with others, spread across the country, on a project. As it is for charity, we are all working in our own time on our personal computers, not all together in one office. Now, how are we to share information if someone works on Windows and another works on Linux?
Of course, there is OpenOffice - which I have used successfully for months to send documents to colleagues who only use Word. Now I have added to my list - GnuCash to handle accounts written with Quicken, MDB Tools to read and import Access databases into MySQL, and a diagramming package called Dia that works on both Windows and Linux.