The Metasploit Framework is a development platform for creating security tools
and exploits. The framework is used by network  security professionals to
perform penetration tests, system administrators to verify patch
installations, product vendors to perform regression testing, and security
researchers world-wide. The framework is written in the Ruby programming
language and includes components written in C and assembler.

This is just a repackaged version of the installer you get from the Metasploit
download page. As the framework now depends on ruby-1.9, which is not yet
mainstream, the Rapid7 Metasploit team decided to distribute an all-in-one
installer with everything needed inside it, both for the ruby side and the
subversion one.

An optional cron script to keep the framework up to date is distributed inside
the /usr/doc/framework-3.3 directory. Also, note that the install directory
has been switched to /opt/metasploit3.