Some background on Eratosthenes and technical stuff about his work. Click.
Investigate some patterns that are formed from the sieve. Click.
Some VERY cool applets (programs) to explore the sieve, prime numbers estimating
pi, geometric solids and some games. Click.
(Requires Java-capable browser.)
A colorful, simple, visual explanation of the sieve. Click.
*** An awesome applet that will show you the
primes to 400. Click.