Oralce offers their 10g database named Express edition at no cost to distribute on Windows and Linux platforms. It has a footprint of only 150 MB and is restricted to the use of a single CPU, a maximum of 4 GB of user data. Although it can install on a server with any amount of memory, it uses a maximum of 1 GB. Support for this version comes exclusively through on-line forums and not through Oracle support.

Can be downloaded from here

A point for MS fans: Oracle came up with this idea, only after MS launched their MSSQL Sever 2005 Express Edition for free

Hope the techies out here, find this helpful & useful