Some of the projects that use MD5 as the default method for storing user passwords include WordPress, osCommerce, SuiteCRM, miniBB, SugarCRM, CMS Made Simple, MantisBT, Phorum, Observium, and X3cms.
Hashing is a one-way cryptographic function while encryption is designed to work both ways. Encryption algorithms take input and a secret key and generate a random looking output called a ciphertext.