WordPress is open source. Yoast SEO is open source. At Yoast, we’re open source fanboys (and fangirls). We’ve talked about it, we’ve written about it. And still, lots of people do not know why open source is so unique. Most people do not even know what open source software is or how it’s made. That’s …Read: "A big shout-out to open source"
At Yoast, open source is at the heart of what we do. We even dare say that the existence of our company, is partly due to the open source model. We truly believe that with openness and joint efforts we can create better code, products, websites and perhaps even a better world.
That’s why all our plugins are open source, as is our flagship plugin, Yoast SEO. We don’t just open up the source code, but we encourage other people to help us improve it as well. In return, team Yoast also contributes to the betterment of WordPress itself.