What Portal mod is shown in VNN's "Steam Store Major Changes" video?

Apparently the footage is from Aperture Dèjá vu; a mod for Portal 1 released in 2009.

[Aperture Dèjá vu] is a non-linear map which have many paths to take and reach the end. The point is, that you play a map one time and you are happy. Then you have a little break in Portal, because there aren't any new released maps for some time. But the answer is here: play the Deja-Vu again, but choose a different path with different puzzles. You can choose freely the way that is going to lead you to the end.

^{Aperture Dèjá vu's ModDB summary}

You can see the name of the mod shown on the Portal Gun itself.