Hadoop是用java写的分布式计算平台。它主要包括了一个分布式文件系统HDFS和一个MapReduce计算模型，这两个模块的设计都是借鉴了
google在分布式系统上的经验。
"Hadoop is a Free Java software framework that supports data intensive distributed applications running on large clusters of commodity computers. It enables applications to easily scale out to thousands of nodes and petabytes of data"
目前windows上还不能直接跑hadoop,但是通过cygwin来模拟linux来运行，效率可能低了不少.
I have ever installed the service , and successfully run the demo word count mapreduce program.
It seems much cool and fancy. You can use this architecture to analyze your log files or some other heavy data-generated applications.