I have contributed two patches to an open-source project and contributed documentation to another.
One got accepted because it solved a long-standing spelling error for a macro that "nobody used, but what the hay, let's merge it because it's valid".
Another was not accepted, but pending whether I can come up with similar functionality for the other toolkits, it may be. The third was documentation for configuring a piece of software (
now an abandoned project) that had NONE when I was trying it out, and I weighed two options: send hate mail (because it was
that frustrating) or put in writing what of it I had managed to grok and submit to the author. I and the (then) project maintainer were glad I chose the latter.
So, all in all, I've had good experience with it. Great article either way.