Unless I misunderstand, this is dead and more or less replaced with Tizen.
 * [[https://meego.com/developers/ui-design-guidelines/handset|Handset UI Design Principles]]
 * [[https://meego.com/developers/meego-ux-design-principles|UX Design Principles]] A brief, neat overview of how to approach the overall interaction of the OS.
 * [[http://www.forum.nokia.com/info/sw.nokia.com/id/eb8a68ba-6225-4d84-ba8f-a00e4a05ff6f/Hildon_2_2_UI_Style_Guide.html|Hildon UI Guidelines for Nokia Maemo]]
 * [[http://meego.com/developers/ui-design-guidelines/handset|MeeGo UI Design Guidelines for Handset]]