Yes, I'm interested too
Here's the user space exploit source code:
https://bitbucket.org/Marionumber1/wiiu-userspace/srcIt is compatible till firmware version 5.1.0 only.
Note:
According to Marionumber1 a Wii U kernel exploit is needed before RAM hacking a.k.a PPC access is possible since the browser is its own sandbox where one needs to "break out".
However, there is no public kernel level exploit. Chadderz found one which he used to mod Mario Kart 8. He also said that Gecko.Net could be used / ported to work for the Wii U but there are no known details on it. For the reasons of preventing online cheating and piracy things are withhold.
A new user space exploit is in the works, but nobody currently knows if the existing kernel exploit still works on the newest firmware version (but most likely it does since Nintendo couldn't have known it) therefore you're out of luck for now anyways if you updated your Wii U to a version greater than 5.1.0.