ScienceDirectory.info is a leading science website including agriculture, metrology, industrial engineering, earth sciences, geography, mathematic, aquaculture, aerospace and more.
SkyQuery
Prototype of a Federated database application, relying on several data sets: the Sloan Digital Sky Survey, the 2MASS project, and the First radio survey.
http://www.skyquery.net/
SpacePix
Photographs and explanations of astronomical objects and spacecraft.
http://www.spacepix.net/
Stig's Sky Calendar
Explore the yearly dance of the Sun, Moon and planets.
http://www.skycalendar.com/
Virtual Sky
Portal to multiple representations of the night sky, including a high-resolution optical survey of the Northern sky and the Uranometria engravings from 1603.
http://www.virtualsky.org/