Build a Beta Dynamic Crawler and Indexer

We are looking at creating a beta dynamic web crawler and indexer. The crawler should be dynamic which means indexing of sites should be continuos rather than having it to tell which sites to index. We want to achieve this through backlinks and also use the google algorithm of page rank in order to show results. You are free to use the opensource tools available out there or you may have already built one. If so get in touch :) Ideally only bid if you can deliver in a short space of time. Thanks