Other than that, unless someone here downloaded all of arcsynthesis before it was taken down, there's nothing really else you can do. Which is a shame, because that was a fantastic beginners site.
Here, I'm currently learning OpenGL from this resource/tutorial aaaand I knew something like this can happen (but in a far future D: ). I downloaded the tutorial two months ago, so here, you can download it.
I will delete the link when website its up again
EDIT: Deleted link by 2016-08-16 because full source and documentation can be found in the bitbucket repository as said in the last message (see the quote)
Eh no need to use the way back machine. If you followed the tutorial, at the beginning it says you should download the tutorial files from a BitBucket repository:
The PDF version of the tutorial is inside the file.