The online etymology dictionary is the internet's go-to source for quick and reliable accounts of the origin and history of English words, phrases, and idioms. It is professional enough to satisfy academic standards, but accessible enough to be used by anyone. The site has become a favorite resource of teachers of reading, spelling, and English as a second language.
Access to hundreds of pages of award-winning information on prime numbers--with links to thousands of pages elsewhere. We host the searchable database of the 5000 largest known primes (updated weekly). We also have a glossary, top 10 records lists, prime-music, programs, free downloads, and much more!