Livefyre

 Livefyre  is an Enterprise Social Web Platform used by hundreds of Publishers and Brands for commenting, chat, reviews, and social content marketing.

Products (Social APIs + Social Web Components) include:
 * Real-time Commenting and Chat
 * Ratings and Reviews
 * User/Topic Following and Aggregation
 * Content Collection Hosting and tools for curating social Content from SNS like twitter.com, instagram.com, facebook.com, and many more
 * A JavaScript SDK for building custom social web components
 * An App Web Service that models application lifecycle management for social web components
 * User Management and Social Authentication
 * https://storify.com/

For more answers, visit Livefyre Answer Central.

History
Livefyre was originally a commenting silo similar to Intense Debate or Disqus.