Dun and Bradstreet, now officially known as D&B, is the premier source for information about corporations and other businesses. Their reports are not free, but are very comprehensive. Here is a description from the site:
D&B is the world’s leading source of business information and insight, enabling companies to Decide with Confidence® for 165 years. D&B’s global commercial database contains more than 100 million business records. The database is enhanced by our proprietary DUNSRight® Quality Process, which transforms the enormous amount of data we collect daily into decision-ready insight. Through the D&B Worldwide Network – an unrivaled alliance of D&B and leading business information providers around the world – customers gain access to the world’s largest and highest quality global commercial business information database.