As a huge portal fan, I’m delighted to read we can already taste some prequel goodness through this great mod.
Apparently, the author worked on it very secretly for some time so obviously he was very disappointed when Valve announced it would also make a prequel. 😉 However this motivated him to finish it as soon as possible. Also, Valve didn’t see any problem or violation in this project and even offered its help.
Thanks to Klaas for the tip.