Applications Using MongoDB
Content Management Systems
HarmonyApp - Harmony is a powerful web-based platform for creating and managing websites. It helps connect developers with content editors, for unprecedented flexibility and simplicity. For more information, view Steve Smith's presentation on Harmony at MongoSF (April 2010).
c5t - Content-management using TurboGears and Mongo
Websko - Websko is a content management system designed for individual Web developers and cooperative teams.
Graylog2 - Graylog2 is an open source syslog server implementation that stores logs in MongoDB and provides a Rails frontend.
Analytics Applications
Hummingbird - Hummingbird is a real-time web traffic visualization tool developed by Gilt Groupe.