How significant is Open Source

More history.  These are quotes from itsolutions.com:

Jeremy Zawodny, Yahoo! -- Open Source at Yahoo!
In this presentation, Jeremy Zawodny talks about how Open Source software scales at Yahoo! He discusses how Yahoo! leverages Open Source software to scale its system. Yahoo! recently acquired Konfabulator and Flickr and Zawodny explains how Yahoo! is changing internally to cater to Web 2.0.

Kartik Subbarao, Hewlett Packard -- Enterprise IT: Open Source Powerhouse
How can enterprise IT organizations embrace open source but still meet their critical individual business requirements? This presentation from Kartik Subbarao at HP provides a successful framework illustrated with numerous real-world examples in production at HP.
Paul Graham, Author of Hackers and Painters -- OSCON 2005
Paul Graham, popular essayist and Lisp programmer, discusses what business can learn from open source. According to him, it's not about Linux or Firefox, but the forces that produced them. He delves into the reasons why open source is able to produce better software, why traditional workplaces are actually harmful to productivity and the reason why professionalism is overrated.

Tony Gaughan, Senior VP of Product Development, Computer Associates -- Open Source Licensing Issues
Open Source software has yet to make substantial inroads into the Enterprise market, but when companies as established as Computer Associates not only release a technology as powerful an the Ingres database but also continue to build their enterprise applications on that platform, the combination adds stability to Open Source efforts. In this Keynote from O'Reilly's 2005 Open Source Convention, Tony Gaughan, Senior VP of Product Development at CA, discusses CA's decision to release the Ingres database to the open source community.