I always learnt a lot from Open Source projects and I use them all the time in fun & customer projects. So it's good to also involve and give back to the community.
When you work with me you also support those projects as I spent at least 25% of my work time on contributions.
If you use my work in your projects or you simply like what I'm doing, you might want to help me continue to invest my time in Open Source. Read more about this topic and how to support me in my blog post.