Maurizio Boriani <baux@member.fsf.org>
	Main design and initial implementation.

Linas Vepstas <linasvepstas@gmail.com>
	Numerous bug fixes.


Assorted fixes and patches:
---------------------------
Jonathan Towne <js.towne@gmail.com>
Andrew Gaylard <ag@computer.org>
Julian Kalbhenn <jkal@gmx.net>
tantalum@online.de
宋文武 <iyzsong@gmail.com>
