Evan came up with x11 and it was absolutely revolutionary and as such has been widely used and cloned into x13 ,x15 ect
there has been no credible evidence presented that it is insecure in any way.
Chaining hashing algorithms is neither revolutionary nor clever.
When you chain hashing algorithms bad things happen:
http://blog.ircmaxell.com/2015/03/security-issue-combining-bcrypt-with.htmlTo quote that blog: "
The underlying problem is that combining cryptographic operators that weren't designed to be combined can be disastrous. Is it possible to do so safely? Yes. Is it a good idea to do it? No. This particular case is just one example where combining operations can be exceedingly dangerous. But the bottom line: never roll your own crypto. It can have fatal consequences."
So he designed something that is (unwittingly or knowingly) open to preimage attacks...and that's revolutionary?