ZoomInfo, which has a free search engine as well as fee-based services, provides users with search options to: Find Person by Name, Find Employees by Company, Find Alumni by University, and to Find People Mentioned on a Specific Website [see this Advanced Search page]. Data retrieved on individuals varies in regard to its scope, consistency, specificity and accuracy withing what should be appropriate context, so note that this is not a one-stop source for background data on individuals.
A search I conducted on a top 10 law firm returned the names of individuals no longer with the firm, but correctly listed their present positions/affiliations, as well as summaries of current members that included education and employment data, related affiliations and relevant news articles. The data mining and aggregating company, formerly Elyion Technologies, obtains its information by spidering and indexing the public web. Registered users may update/change their bios.