SEO and web research for competitive keywords ,PageRank ,and anything like that may take you a lot of time . In internet ,there are many services ,and each of them can do only several tasks ,so you have to pass over many sites for completing the research .

But I found an interesting website ,it contain 77 free tools for SEO and web research

 Tools are organized in 11 categories

- Link Tools : for analyzing links and backlinks

-Keyword Tools : researching keywords

-Authority Link Tools : analyzing backlinks and rank in Web directory

-Search Engine Tools : Check web index ,web crawling ... in popular search engine

-Website Rank Checkers : Check website rank in popular ranking system such as Google PageRank ,Yahoo Rank or Alexa

-Multi-Site Rank Checkers : check multi-site for comparation

-Header/Tag Tools : analyzing site header ,meta tag...

-IP Tools : Check ip ,ping domain...

-Miscellaneous Tools : Check web status ,convert units ...

-Source code Tools : validate CSS,Encrypt website ...

-Social Web Tools : Check links in social networks .