Everyone knows "Garey & Johnson", which is my go-to reference whenever I need a problem to transform from for an NP-hardness proof. However I recently find myself in need of an APX-hardness proof, and I wonder if there is a similar (and more up to date..?) collection of problems that have been shown to be APX-hard.
Does anybody know of anything like this? I find it hard to believe that there is no website systematically collecting such problems, but my Google skills seem to be insufficient.
