I agree with the comments in this thread, and I add that Facebook knows fanboys are stupid and there are a lot of them, so they try to take advantage of it.

> Buck: A high-performance build tool

And in the title you read "a fast build tool", like yarn, as soon as it was released it was the faster one.

F: let's use yarn/buck G: why? F: cause it is faster G: Did you already tryed it? Did you measured or benchmarked it? F: No, but Facebook claims it is fast, come on!

By the way, sometimes yarn does not work and you need to add a file to manage it. Furthermore facebook is using the npm registry, do they pay for it or support it?

Other than that, thanks to Facebook to bring awesome tools to the public, like React.