I was going through some sites and found a good information regarding the events that happened in the past and which brought up Oracle to this place. Thats being a long journey of Oracle business spreading right from database to application and middle tier architecture.

Here are the brief events I have listed.

• 1979: Larry Ellison and friends founded Software Development Laboratories.
• 1979: SDL changed its company-name to “Relational Software, Inc.” (RSI) and introduced its product Oracle V2 as an early commercially-available relational database system. The version did not support transactions, but implemented the basic SQL functionality of queries and joins. (RSI never released a version 1 – instead calling the first version version 2 as a marketing gimmick.)
• 1983: RSI in its turn changed its name, becoming known as “Oracle Corporation”, to align itself more closely with its flagship-product. The company released Oracle version 3, which it had re-written using the C programming language and which supported COMMIT and ROLLBACK functionality for transactions. Version 3 extended platform support from the existing Digital VAX/VMS systems to include Unix environments.
• 1984: Oracle Corporation released Oracle version 4, which supported read-consistency.
• 1985: the Oracle RDBMS began supporting the client-server model, with networks becoming more widely available in the mid-1980s. Oracle version 5.0 supported distributed queries.
• 1989: Oracle Corporation entered the application products market and developed its ERP product, Oracle E-Business Suite, based on the Oracle relational database. Oracle RDBMS version 6 came out with support for PL/SQL embedded within Oracle Forms v3 (version 6 could not store PL/SQL in the database proper), row-level locking and hot backups.
• 1992: Oracle version 7 appeared with support for referential integrity, stored procedures and triggers.
• 1997: Oracle Corporation released version 8, which supported object-oriented development and multimedia applications.
• 1999: The release of Oracle8i aimed to provide a database inter-operating better with the Internet (the i in the name stands for “Internet”). The Oracle 8i database incorporated a native Java virtual machine (Oracle JVM).
• 2001: Oracle9i was released with 400 new features, including the ability to read and write XML documents. 9i also provided an option for Oracle RAC, or “Real Application Clusters”, a computer-cluster database, as a replacement for the Oracle Parallel Server (OPS) option.
• 2003: Oracle Corporation released Oracle Database 10g. (The g stands for “grid”; emphasizing a marketing thrust of presenting 10g as “grid-computing ready”.)
• 2005: Oracle Database 10.2.0.1 — also known as Oracle Database 10g Release 2 (10gR2) — appeared.
• 2007: Oracle Corporation released Oracle Database 11g for Linux and Microsoft Windows.

 Oracle Database versions

Since version 7, Oracle’s RDBMS release numbering has used the following codes:

• Oracle7: 7.0.16 — 7.3.4
• Oracle8 Database: 8.0.3 — 8.0.6
• Oracle8i Database Release 1: 8.1.5.0 — 8.1.5.1
• Oracle8i Database Release 2: 8.1.6.0 — 8.1.6.3
• Oracle8i Database Release 3: 8.1.7.0 — 8.1.7.4
• Oracle9i Database Release 1: 9.0.1.0 — 9.0.1.5 (Latest current patchset as of December 2003)
• Oracle9i Database Release 2: 9.2.0.1 — 9.2.0.8 (Latest current patchset as of April 2007)
• Oracle Database 10g Release 1: 10.1.0.2 — 10.1.0.5 (Latest current patchset as of February 2006)
• Oracle Database 10g Release 2: 10.2.0.1 — 10.2.0.3 (Latest current patchset as of November 2006)
• Oracle Database 11g Release 1: 11.1.0.6 — no patchset available as of October 2007

The version numbering syntax within each release follows the pattern: major.maintenance.application-server.component-specific.platform-specific.For example, “10.2.0.1 for 64-bit Solaris” means: 10th major version of Oracle, maintenance level 2, Oracle Application Server (OracleAS) 0, level 1 for Solaris 64-bit.

Reference: Wikipedia