In March of 2006, IBM made a strategic decision to release their best of breed DB2 database as freely available software. It is important to realize that the DB2 Express-C edition is a gratis, "free as in beer" software product, meaning that, although the source code is not distributed as part of the product, this edition of DB2 is freely useable and full featured, not "crippled" in any way.
A number of other large enterprise class databases have also opted to release versions of their software, but DB2 Express-C is the only one that places no restrictions on the size or number of the databases that can be created. The one restriction to using DB2 Express-C is that it can only be run on systems with 2 physical CPUs and 4 GB of RAM. Since the majority of developers and small businesses run systems within these specifications, DB2 Express-C makes a great choice for developers and business applications. In this HOWTO, all testing and discussions are based on machines that fall within these system specifications.
With DB2 Express-C, you get a free, low maintenance database application that is easy to install and run, with a number of powerful features, as well as performance typically found in much more expensive enterprise-level database software.