Lintian is a Debian package checker. It can be used to check binary and source packages for compliance with the Debian policy and for other common packaging errors.
Lintian uses an archive directory, called laboratory, in which it stores information about the packages it examines. It can keep this information between multiple invocations in order to avoid repeating expensive data-collection operations. It's also possible to check the complete Debian archive for bugs — in a timely manner.