DVDSubEdit is a program that allows you to edit the contents of a DVD, whether it be subtitle, menu or any other element that is part of the VOB files included in the DVD.
You can make various modifications to the subtitles, such as editing, changing their color, changing the transparency level, changing the time a text appears, synchronizing it (in case there is a mismatch between the image and the titles, it can be adjusted by varying The start time), remove parts (for example the text that guides the hearing impaired), and some more functions.
Changes made to subtitles can be recorded in the same.VOB file, but can also be exported to specific files of type .SUP or .SRT.
DVDSubEdit 1.5.2 is the latest version (updated September 2011) of this software that you can download for free and install on Windows. Some improvements are made, such as supporting VOB files larger than 1 Gigabyte, and some bugs present in the previous version are fixed.