Libnss-mysql-bg provides a name service switch module that allows mysql to act as a name service.

its configuration is very flexible by allowing to set an sql query per nss call (getpwnam, getpwuid, ...). you would use it instead of the other "libnss-mysql" package for building an nss over an existing database (used for another purpose like groupware, ...).

it currently supports storage of passwd, group and shadow information.