Transmission is written and maintained by:

Eric Petit <titer@m0k.org>
 + Back-end
 + OS X interface

Josh Elsasser <josh@elsasser.org>
 + Back-end
 + GTK+ interface

Bryan Varner <bryan@varnernet.com>
 + BeOS interface

Michael Demars <keul@m0k.org>
 + OS X interface (Growl notifications, AppleScript)
 
Mitchell Livingston <livings124@gmail.com>
 + OS X interface

Thanks to:

Omar and Adrien
 + Beta testing

Various people
 + Writing http://wiki.theory.org/BitTorrentSpecification

vi@nwr.jp
 + Free SHA1 implementation (sha1.[ch])

John Blitch
 + OS X patch (Contextual menu)

Ahmad M. Afuni
 + NetBSD patch

Jeremy Messenger
 + FreeBSD patch

Mike Matas <http://www.mikematas.com/>
 + OS X toolbar icons

Martin Stadtmueller
 + Icon tweaking

FOOOD
 + Badging images, Progress Bar images
 
Rashid Eissing
 + Transfers preferences icon
 + Interface conceptualization