Zotero is a free reference management application. It is open-source, and therefore cannot be acquired by a company.
Zotero allows you to:
Store and organise your references
Insert references and bibliographies into a word processor document
Use your computer’s chosen PDF viewer to access PDFs.
Collaborate by sharing libraries
Zotero is a desktop product that can be used in conjunction with a zotero.com login. It has an adjunct product: Zotero Connector. This is a browser extension that allows you to capture citation information from websites, including bibliographic databases.
Zotero is easy to use and is supported by informative help pages and forums.