An Online Research (Software/Services)

Do an online research / search: 1. Find a opensource software for vulnerabilitiy monitoring 2. Sources of informations which certain websites/services use (whitepages, etc). Find out where people search sites aggregate their information from, primarily for within US. 3. Find an opensource software for parsing website content with specific requrements (turning webpage content into structured data, detect webpage changes, should be maintained and performant, preferebly Java but not necessary, ) I need a document that will contain couple of examples for each point (best options/tools available online), with differences/pros&cons between those examples (point 1 & 3). Regarding the point 2. as much details as possible related to the subject.