Firebird File Version RazorSQL includes Firebird clients for connecting directly to Firebird files on the local machine. RazorSQL includes clients for Firebird versions 2.5 and 3. When accessing a file on the local machine, RazorSQL needs to know the version number of the file so it can select the correct client. The Firebird 2.5 client can connect to files created with Firebird versions 2.0 through 2.5.