AlgaeBase offers a free database of information on algae species around the world. This project is part of the Species 2000 initiative, created to enumerate "all known species of plants, animals, fungi and microbes on...

More than 50 "informal notes" by Kevin Brown on algebra. Kummer's Objection; irreducibility criteria, multiple linear regression, string algebra, characteristic polynomial of a matrix, iterated means, sums of powers,...

Algebra.help is an online resource designed to help people learn algebra. It offers lessons to teach or refresh old skills, calculators that show how to solve problems step-by-step, and interactive worksheets for testing...

The Space Telescope Science Institute's Amazing Space site is the product of teachers teamed up with scientists, engineers and staff from the institute. This site has interactive lessons in astronomy and math designed...

This collection of teaching tools, authored by the Space Telescope Science Institute (U.S.) includes lithographs, fast facts, graphic organizers, question and answer sessions, and online explorations on an array of...