It couldn't be a better time to start using open source software. A client is more willing to expand the scope of a project and not be so price conscious when the software they will be using is free. The budget for the project is used to pay for your services and on going support. You remove the risk and give the feeling that life can go on if you or your company doesn't. It's much harder to get a client to take on new projects these days not knowing what the ROI may be. With open source software you can provide solutions that are already available which you can use as is or integrate into your custom solutions. You can be more competitive against larger commercial solutions because you have the open source community behind you covering your back. Linux and the many php based offerings are proof the concept works.
It's all about using shared resources and creating a community of users/VARS that take ownership into the software they use. Open source software in general is more secure, better written and supported. The more eyes your have looking at the code the more stable it will be. Contribute your time to projects you plan to use to solve your clients needs.
