Gnome Subtitles + Bombono = Nice DVD/Subtitle Solution for Linux

Bombono DVD Open Source Authoring Software
Bombono DVD is a DVD authoring program for Linux. It is made easy to use and has nice and clean GUI (Gtk).

The main features of Bombono DVD are:

Excellent video viewer: Timeline and Monitor
Real WYSIWYG Menu Editor with live thumbnails
Comfortable Drag-n-Drop support
Transcoding, if necessary (from AVI/MKV/MOV/MPEG4…)
Motion menus
Subtitles support
You can author to folder, make ISO-image or burn directly to DVD
Reauthoring: you can import video from DVD discs
Bombono DVD is Open Source software and freely distributed under GPL license.

Gnome Subtitles:

Gnome Subtitles is a subtitle editor for the GNOME desktop. It supports the most common
text-based subtitle formats and allows for subtitle editing, translation and synchronization

Other Captioning Tools and Resources