Quora is a collection of questions and answers created, edited, and organized by everyone who uses it. Quora is the new Answers.com
People write their own answers to questions any time they think a question page could become a better resource with more information added to it and People can follow topics so that the system can show them questions they are interested in and know about.

There are Quora alternatives for the enterprise out there. The following three serve enterprises with all the questions you want to ask and all the answers you need.

Opzi is a service for organizations building internal Q&A sites. It’s currently in private beta. It will use a Yammer-like model: users will sign-up with their company e-mail address and will then be able to ask and answer questions specific to their company.

MindQuilt is an enterprise knowledge management platform with intelligent question and answer matchmaking and gaming achievement dynamics.

Focus makes the world’s business expertise available to everyone. At the heart of Focus is a network of thousands of leading business and technology experts who are thought leaders, veteran practitioners and upstart innovators in hundreds of different topics and markets.