Every two years, SEOmoz surveys top SEO experts in the field worldwide on their opinions of the algorithmic elements that comprise search engine rankings. This year features contributors from the US, UK, Canada, Australia, New Zealand, Iceland, the Ukraine, the Dominican Republic and many more.

Each participant was asked to rate more than 100 search ranking factors along with specific questions about hot issues in the SEO field. This document, representing the collective wisdom of expert practitioners, is, in opinion, one of the most useful resources for SEO practitioners of all varieties, helping to provide transparency into what matters (and doesn’t) for best practices in search engine optimization.

Read more http://www.seomoz.org/article/search-ranking-factors

SimilarSites is a search engine helps you find web sites which are relevant to the URL you searched on Similarsites. It has Browser Add-ons for both Firefox and Internet Explorer to provide easy access to relevant web sites and content.

Compass is a first class open source Java Search Engine Framework, enabling the power of Search Engine semantics to your application stack decoratively. Built on top of the amazing Lucene Search Engine, Compass integrates seamlessly to popular development frameworks like Hibernate and Spring. It provides search capability to your application data model and synchronizes changes with the datasource. With Compass: write less code, find data quicker.

As of version 0.8, Compass also provides a Lucene Jdbc Directory implementation, allowing storing Lucene index within a database for both pure Lucene applications and Compass enabled applications. Note, when using Compass, using a database as the index storage requires only updating configuration settings.>>Reference Documentation