I've been eating Cross & Blackwell's chow-chow since I was a child, and there's nothing like it and no replacement that I've found.  It's impossible to buy in groceries where I live, but now I can buy it online!  It's not quite as great as it was when I was younger, when it had whole pearl onions and largish chunks of cauliflower in it, but the taste is the same.  It would be even better, though, if it were more as it was before.  It's a great condiment.