Mailing the story:

The is a clear pattern to open source's continuing rise. The first free software that was deployed was at the bottom of the enterprise software stack: GNU/Linux, Apache, Sendmail, BIND. Later, databases and middleware layers were added in the form of popular programs like MySQL and Jboss. More recently, there have been an increasing number of applications serving the top of the software stack, addressing sectors like enterprise content management, customer relationship management, business intelligence and, most recently, data warehousing.