DVDStyler is a crossplatform DVD Authoring System. It is free software distributed under GNU General Public License (GPL).

Features:

you can drag and drop MPEG files directly
you can import image file for background
you can create NTSC/PAL menus
you can place text and images anywhere on the menu screen
you can change font/color
you can put basic text buttons, change font/color and background color
you can copy and paste any menu object
you can set chapters for each movie
you can change post command for each movie