Readymag - Readymag is a design toolkit that helps create immersive digital experiences without developers in days, not weeks.
Interfacer - Collection of more than 200+ free design resources
Publiseer - Publishing should be free and easy
Facebook Design Resources - A collection of free resources made by designers at Facebook
VirtualPaper - Virtual Paper is a digital publishing for converting offline pdf documents into online content.
Freebiesbug - Collection of the best free web design resources.