I've played with Nutch, and looked at Hadoop, and it's pretty cool stuff. It's also a great foundation for building Google-style solutions to embarrassingly parallel applications. Combine it with Amazon's EC2 and things look really interesting...
I'm glad to see Yahoo supporting/contributing to the community in this way. I think it's stretching the point to call it a 'challenge to Google' - more Yahoo seeking to level the playing field a little.
If you want to get your hands on an open source version of some of Google's core technologies, maybe you should ask Yahoo.
Yahoo has emerged as one of a major sponsor of Hadoop, an open source project that aims to replicate Google's techniques for storing and processing large amounts of data distributed across hundreds or thousands of commodity PCs.
I'm glad to see Yahoo supporting/contributing to the community in this way. I think it's stretching the point to call it a 'challenge to Google' - more Yahoo seeking to level the playing field a little.