Errbit is an opensource error tracker that follows the Airbrake API. It uses Ruby on Rails, and Mongoid to connect to MongoDB.
The code is maintened by a few people, and we are very active at GitHub, so we follow the GitHub open source flow of Pull Requests, Issues, and merges. All new contributions are welcomed and highly appriciated. We are also looking for more projects maintainer to make sure the project is always being pushed foward.
As a production environment, we use errbit extensively at Shopify, and we are willing to test/help with new features. I will be the main mentor for this project, but we also have an IRC channel to make sure we are always on top of communication and no question is unanswered.