Evolvement of Oracle releases.

In 1992, Oracle released its version 7 for UNIX.

In 1994, there came out the version 7.1.

In 1997, Oracle 8 was released; its prime features included more scalability and object relational features.

In 1999, Oracle 8i came out equipped with internet technologies.

In 2000, Oracle 8i Release 2 with Oracle 9i Application Server (AS) was released. 

In 2001, Oracle 9i R1 wade made public.

Its major features include Real Application Cluster (RAC) and analytical functions. 

In 2002, Oracle 9i R2 got released. In 2004, Oracle 10g was released, the first ever database to support grid infrastructure.

In 2005, Oracle 10g R2 was commercialized for major platforms. 

Now is 11g 

HTH:-)