An algorithm created in 1991 by Professor Ronald Rivest that is used to create digital signatures. It is intended for use with 32 bit machines and is safer than the MD4 algorithm, which has been broken. MD5 is a one-way hash function, meaning that it takes a message and converts it into a fixed string of digits, also called a message digest.

When using a one-way hash function, one can compare a calculated message digest against the message digest that is decrypted with a public key to verify that the message hasn't been tampered with. This comparison is called a "hashcheck."
(quoted from webopedia.com)

Project md5(); can help you with two things. First of all it can help you to cryptate a string with md5 cryptation. But the reason this site is realy here is because you can run a dictionary attack agenst your md5 hash. In other words, it is here to help you with decrypting your md5 hashes.

However if you are not of the cracking or hacking type, this site can provide you with a database full of commonly used passwords. Passwords that is un-safe to use. Therfore it can be wize to look up your password here before taking it into use, so you know your password is a un-common password. (that is if the result turns out negative).

Webmasters can also use this site to run their registration scheems trugh the database before allowing a user to choose his password, to ensure that the password is not un-safe to use. (See the xml output readme site for more info)

Basicly you can find the strangest keys in this database. That is because everytime a user types in a word in the search engine it gets added to the database. Other than words comming in from all over the world from every surfer that is passing bye this site, the Project md5 database has specialized itself around a few key spots:

• Commonly used passwords
• Commonly used English/American words
• Commonly used Norwegian words
• Latin Words
• 1-5 digit pins