title: Which file based DBMS should I support in an open source project?
body: <p>I am working on an open source project which can use a number of DBMS' as backend. So far we supports SQL Server 2005 and SQL Server 2008 but we would also like to support some additional databases including some file based DBs.</p>
  
  <p>Note: The file based databases must work on a 64-bit platform, so MS Access is not an option as there is no 64-bit provider AFAIK.</p>
  
  <p>Which DBMS should a database centric open source project support in your opinion?</p>