Hi, I just noticed that Niocchi has been released recently. http://www.niocchi.com/
Niocchi is a java asynchronous crawl library implemented with NIO. It is designed to crawl several thousands of hosts in parallel on a single low end server.It is currently being used in production by Enormo<http://www.enormo.com/> to crawl thousands of websites daily, and by Vitalprix<http://www.vitalprix.com/> . Regards, Lukas