vDos derived from the DOSBox project (http://sourceforge.net/projects/dosbox/).
DOSBox is targeted at gaming and available for many operating systems.
If you consider using it for a database application. DON’T, mostly you’ll end up with corrupted data.
vDos is for serious (mainly text mode) DOS applications, Windows 32/64 bits (XP and later) only.
It lacks many of the hardware emulations of DOSBox (no joysticks, basic VGA...).
Instead it adds a live file system, file/record locking, Windows printing, a scalable screen font and more.
You should be able to run your DOS application quickly in a safe and convenient way.
WP users should first have a look at:
http://www.columbia.edu/~em36/wpdos/vdoswp.html
Mac/OS X users:
http://www.wpuniverse.com/vb/showthread.php?36046
