One of the great things that I've recently noticed about working with Open Source and Free Software in general is the portability of that knowledge, code and experience.
We're currently starting up a new project at work, and it's great being able to reuse the knowledge of lots of 3rd party libraries, projects, designs and code that we've been exposed to via our involvement with Cocoon, Avalon and open/free software in general.
This really helps us focus on the real business of what we're trying to achieve, and keeps us from being bogged down in low level technical ground work, which is great.