Hmmm, well, VMWare is a virtual machine environment. After you install VMWare, you also need to install one or more guest operating systems. I've used MS Windows98 and NT4 Work Station, both with fine results. If you're saving the data to a portable format, you can then use the files under Linux or whatever you want.
Text files work fine, for instance.
MySQL databases might be okay too. You can find an eval version there. It's not free in any sense of the term. Look at Tk. It can run cross platform.