Index/Search for web site or web portal

[macmesser]

I'm looking for a software which will provide advanced search capabilities for my web site and which will index pointed-to sites on the web and return complex search results. The object is to provide a field-wide business portal for customers and staff. This could also be automated for web-crawling and internet data mining. I have looked at Devon Technologies' DevonSphere server and it seems ideal but unfortunately it is apparently not yet available for purchase even though it appears on their web site at the link below:

http://www.devontechnologies.com/products/devonsphere/devonsphere-server.html

Does anyone know of a possible alternative to this product?

Thanks for any insights.