Interfacer - Collection of more than 200+ free design resources
Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
Blush - Illustrations for everyone
Craftwork - A collection of User Interface resources made by Craftwork
Freebiesbug - Collection of the best free web design resources.
Streamline - Streamline is a web-based vacation rental software that manages vacation rental properties with flipkey integration, online booking, lead management, credit card processing, etc.