Generalized Fermat Prime Search
- Software, results and other resources.
- http://perso.orange.fr/yves.gallot/primes/gfn.html

Electronic Frontier Foundation: Cooperative Computing Awards
- Offers $100000, $150000 and $250000 for the first discovery of a prime above 10, 100 and 1000 million digits.
- http://www.eff.org/awards/coop.php

On-Line Encyclopedia of Integer Sequences (OEIS): Primes
- Index to information about many integer sequences involving primes. Site includes numerous other prime-related sequences.
- http://www.research.att.com/~njas/sequences/Sindx_Pri.html

Wikipedia: Prime Numbers
- Index to many prime-related articles.
- http://en.wikipedia.org/wiki/Category:Prime_numbers

MathWorld: Prime Numbers
- Index to hundreds of prime-related articles in Eric Weisstein's MathWorld.
- http://mathworld.wolfram.com/topics/PrimeNumbers.html

Jens Kruse Andersen
- Prime constellation records. Arithmetic progressions, simultaneous primes, prime gaps.
- http://hjem.get2net.dk/jka

Primality
- Introductory text on the theory of prime numbers and number fields. Contains proofs of some important theorems including the fundamental theorem of arithmetic.
- http://www.maths.tcd.ie/pub/coursework/374/Primality.pdf

Cunningham Chain Records
- Sequences of nearly doubled primes, maintained by Dirk Augustin.
- http://hjem.get2net.dk/jka/math/Cunningham_Chain_records.htm

Bipeds and Prime Numbers
- Graduation address by former professor of philosophy Garrett Barden. Mentions primes as sign of human curiosity.
- http://www.ucc.ie/opa/conferspech/gbarden.html

Number Spiral
- Explains this method of visually representing the distribution of primes and the relationships between factors and products.
- http://www.numberspiral.com/

Prime Music
- A musical piece translating prime factorizations to frequencies. Requires RealPlayer.
- http://www.xs4all.nl/~limonade/limonades/priem/primemusic.html

The Prime Machine
- Explore interactively the Goldbach conjecture, the distribution of prime twins, the prime number theorem.
- http://www.math.utah.edu/~alfeld/math/machine.html

K-Tuple Permissible Patterns
- Findings using an exhaustive search by Thomas J Engelsma.
- http://www.opertech.com/primes/k-tuples.html

Prime Numbers List
- Browse all prime numbers of less than 10 digits. A prime number checker facility is also included.
- http://www.prime-numbers.org

Animation of Eratosthenes' Prime Sieve
- An interactive animation of the sieve of Eratosthenes to obtain prime numbers (JavaScript required).
- http://www.faust.fr.bw.schule.de/mhb/eratosiv.htm

Prime Numbers
- Short lesson.
- http://odin.mdacc.tmc.edu/~krc/numbers/prime.html

Radiant Primes
- Visualization of prime numbers resembling an astronomical radiant or celestial pathway.
- http://www.radiantprimes.com/

The Nine and Ten Primes Project
- The discovery of nine and finally ten consecutive primes in arithmetic progression.
- http://members.aon.at/toplicm/cp09.html

Are the Prime Numbers Randomly Distributed?
- Web article by Johan G. van der Galiën. Shows that smaller starting digits are more common for primes below 10^9.
- http://www.home.zonnet.nl/galien8/prime/prime.html

Hardy-Littlewood Constants
- Infinite series over primes are the main topic in Hadamard-de la Vallée Poussin constants and in Brun's constant.
- http://pauillac.inria.fr/algo/bsolve/constant/hrdyltl/hrdyltl.html

Generalized Woodall Numbers
- An organized search for primes of the form n*b^n-1.
- http://science.kennesaw.edu/~jdemaio/generali.htm

World of Numbers: World of Palindromic Primes
- Records, statistics, curios and puzzles about primes reading the same backwards. Compiled by Patrick De Geest.
- http://www.worldofnumbers.com/palpri.htm

Ask Dr. Math FAQ: Prime Numbers
- Archived questions and answers at different levels.
- http://mathforum.org/dr.math/faq/faq.prime.num.html

Visualizing the Distribution of Prime Numbers
- Investigation into patterns in the distribution of the primes by visualizing them.
- http://yoyo.cc.monash.edu.au/~bunyip/primes/

Applets for Prime Numbers
- Factorization and weights of Proth coefficients.
- http://www.brennen.net/primes/

MacTutor History of Mathematics: Prime Numbers
- Includes biographies on many mathematicians.
- http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Prime_numbers.html

Some Prime Numbers
- Sieves and factoring for small numbers. Download primes below 8 billion.
- http://www.rsok.com/~jrm/printprimes.html

Formulae for Primes
- Contains a formula by Jones, Sato, Wada and Wiens. The set of primes is the set of positive values taken by this expression.
- http://www.bath.ac.uk/~ensab/Primes/

Entropy and Prime Numbers
- Entropy of a nonnegative adjacency matrix related to prime numbers.
- http://web.tiscali.it/GEB/sfteng.htm

Notes and Literature on Prime Numbers
- With applets to demonstrate properties of primes.
- http://www.math.utah.edu/~alfeld/math/prime.html

Primality Testing with Fermat's Little Theorem
- Test numbers for primality and pseudoprimality in Java.
- http://www.math.fau.edu/Richman/carm.htm

Introductory Prime Number Theory Resources
- Notes and links compiled by Mark Watkins on the relation of the Riemann zeta function to the distribution of prime numbers.
- http://www.maths.ex.ac.uk/~mwatkins/zeta/tutorial.htm

Thomas R. Nicely
- Includes twin prime counts, tables of first occurrence prime gaps, papers.
- http://www.trnicely.net

Prime Numbers and Factoring
- Links and references related to primes and factoring.
- http://www.ontko.com/~rayo/primes/index.html