Pretty much every component of our system is made out of open source components I can and have changed/contributed to.
Not every one of these components has a large community behind but sometimes I'm surprised by Pull Requests and Q&A on google groups or stack overflow.
I find it invaluable having direct access to people who have implemented a library, sharing ideas, asking questions about their design.
These days sometimes it feels like I'm not growing as much as I used to, I don't learn entirely new things every day anymore. But looking back, gosh! the progress over the years has been constant and the accumulate knowledge significant. More than anything: written software still appears sound. If I go back, and I look at how certain things got implemented, even smaller things, they look simple and beautiful (not everything of course).
As a proof of that, extending and providing new services doesn't take too long.
Iterative refactoring allows me to consolidate the good things and to get rid of the bad (copy&paste) ones.
I'd like to take a chance and thank all the contributors to these projects:
Force.com Web Service Connector
All Google's Contributions and Resources!
plus several others...
For my contributions in my free time and at work go to:
PS Recently I've been invited to take part of a project related to my latest interest: strabismus and amblyopia.
There's no public information available for this particular project yet but it will eventually become Open Source on GitHub!