WebObjects is kind of like Rails, but 20 years earlier. (Seriously, it's actually very similar to Rails, in it's bones. I don't know if dhh had seen WebObjects, or they just both had seen some smalltalk mvc framework)
They inherited it from NeXT, and it seriously was really ahead of it's time originally. Hell, it was a technically competent and competitive web framework through, oh, 2002 or 2004, maybe even a few years after that. (Can you tell I used to develop for it?)
But it ended up not being a market Apple wanted to be in, selling a web development framework, and it didn't get much attention, it withered on the vine. (Even if it had... 20 years of legacy is not good for a web framework, it would probably still suck by now -- and who wants a proprietary rather than open source web framework, if they can avoid it?). But they kept using it internally anyway long after they stopped marketting it or selling it externally.
Anyhow, it's really hilarious if the legacy WebObjects part of Apple's web infrastructure are actually the parts that are still up. Hilarious in a pleasant way for those of us who used to use and love WebObjects back in the day.