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.

Download Zotero and Zotero Connector

Zotero Help Pages