Well I suppose really--all you need is a program that can rip and decrypt the DVD to your hard-drive. Then any commercial program will be able to take the vob files and work with them from that point, as they will no longer be encrypted.
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I regularly decrypt and rip movies just to watch them on my PC. Many DVD's now use "viewer software" that is usually Windows Media Player plugins that are also basically spyware, and when you insert the DVD into your computer, it tells you that you need to install this driver to watch the DVD--which is bullsh!t. Also--this makes it so that to watch that DVD, you can only use Windows Media Player, even though (in my case) I prefer the features of the DVD-viewing program that came with my videocard.
InterActual is one such plugin, there are a few others.
So to get around that, I use DVDDecryptor to rip+decrypt them to my hard drive, and then watch the vob files with the other program.
.....And then I usually end up deleting the vob files, as very few movies now are worth the cost of a blank DVD, in my opinion.
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