When you're saying "Desktop application", are you saying "Windows" too? Because if that is the case, my advice - albeit unpopular here - would be to avoid Perl and especially Tk (*shudder*) alltogether and go for the .NET route (C# and WPF). The relevant toolchain and IDE is free and you can use .MDB as your data format. You don't even need a MS-Access license for that, even if it helps with debugging.