A major Emacs mode for editing Debian preseed files.
Works well with the powerful allout outline mode that comes as part of GnuEmacs. Check out the screenshots for details.
The preseed.cfg in the master branch gives a comprehensive list of all configuration options in one big file; whereas in the separated branch that big file is broken down to logical pieces, making it easy to customize "locally". For example, the preseed.020-Source can be customized into two flavors, one for Debian and the other for Ubuntu.