Commercial and Proprietary software (CPS) is able to exist quite happily with open source software. The open source desktop productivity suite Open Office, for example, gets along very easily with Microsoft’s Windows XP operating system, even though Microsoft has a competing product in its Office desktop software suite.
Even amongst existing commercial software applications, incompatibilities can be deliberately introduced to break existing structure and induce FUD (Fear, Uncertainty and Doubt). Other vendors might have done it in the past but Microsoft’s vs. DR DOS case has been the most publicised.
More often than not, hardware vendors choose to mix the best of both worlds to provide customers with a compelling solution. Some will bundle Open Office with Windows XP, while server vendors will mix and match, Windows Server, Linux, UNIX on the one hand, with Apache, and proprietary software on the other.
Content creation software developers, however, often choose to be OS centric. Some have an almost sworn allegiance to a specific platform and rarely deviate from it.
For example, you will not find AutoCAD or Flash MX for Linux; partly because it would be lengthy and costly to recode those software packages for the open source OS, but also because it might open a Pandora’s Box that no one will be able to close afterwards.
On the other side, a growing number of companies are jumping on the bandwagon and open sourcing some part of or their whole portfolio and bridging the gap between software-provider and service-provider - IBM being the most notable example
The answer lies perhaps in hybrid CPS/OS (open source) solutions, which combine the best of both worlds; value for money is the bottom line at the end of the day.
You can read about the ten other myths of commercial and proprietary software here.