Hi Bill + Anthony
Happy new year
I was far from my Mac when I saw Bill's post and I didn't have my password to this forum (only my Mac knows it), but after being back home, I tried the new version of the ATK site on my Mac. I can see no change in functionality. (I hadn't noted that Flash was no longer used, but this can only be a positive move.)
I've also checked if the hundreds of puzzles I had solved with my KakuRules solver are still there and yes, I found them. They are still numbered with 5 digits.
I don't know what happened to Bill in his last experiment with the ATK site.
From all the Kakuro sites I had tried when I was writing my last book (PBCS and its 2nd edition PBCS2), the ATK one seemed to me to be the best, in terms of variety of sizes, in terms of variety of the levels of puzzles (though I was mainly interested in the hardest ones), in terms of variety of the patterns of black cells and in terms of readability of the interface. If I may have a wish for this New year, it's you find time to make more of these puzzles.
The kakuro-online site has nice puzzles also, but as Bill says, they are much easier (the "hard" ones are easier than the "medium" ATK ones) and they were less interesting to me for the purpose of testing the power of my resolution rules. They rely too often on splitting the puzzle in 2 or more parts by what I called the rule of "surface sums". I've nevertheless added it to the list of Kakuro references in the first post of this thread.