You have known about OpenOffice and LibreOffice is an open source office and much similar to OpenOffice and the nice alternative to Microsoft Office! 

Like OpenOffice, LibreOffice includes Base, the component module that offer features similar to that of Microsoft Access and allows you to create databases with full ease. This module comes packed with HSQL relational database engine and offers wizard support to help novice users easily design their database schema.

LibreOffice Base is ideal for creating simple as well as complex database applications It provides native support to Base flat files, JDBC/ODBC drivers, and other database engines like MS Access, Adabas D, MySQL and PostgreSQL.

Download FREE LibreOffice Base

Source: ilovefreesoftware