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by Jim Snow last modified Aug 26, 2013 03:55 PM

Our product is a reputation system called Pariah.  It uses reputation data from a social network (i.e. which users like each other, and which users don't like each other), and makes predictions about how well users will get along with each other by analyzing the structure of the relationships in the social network.

You can read more about the design of Pariah here.


Pariah functions as a stand-alone server with a json-based rest interface. A single server can serve as a reputation system for multiple independent online communities.  We also have an implementation of pariah that can be used for offline reputation computation, if batch processing is your thing, and we're working on simple C library for situations where http json requests are overkill.

Pariah is designed to handle large reputation graphs efficiently.  We routinely test with graphs that vary from a few tens of thousands to a few million users.


Pariah is currently in development, but we are looking for a few beta testers at this point.  If you are interested in trying it out on your own site, please contact  Our preference is to distribute binaries to run on your own servers, but we might be able to accommodate a cloud solution if there's demand for that sort of thing.


We have an online demo of the pariah web service up and running, which can be used to try the examples in the user guide, just substitute metamocracy:3000 for localhost:3000 in the examples, and skip the sections on installation and running in batch mode.  Also, understand that the server is designed to be accessed programmatically through a json-based rest interface using something like curl.  There is an html-based interface, but it is there mostly for debugging, it isn't meant as the primary interface.

Please note that

  • the server we're running this on is a dual-core atom,
  • there is no access control, so anyone else can view (or change) anything you do, and
  • the demo server only allows reputation systems to be created with no more than 1000 users.

In other words, the demo server is for demo purposes only.  Please don't use it for live data.

If the demo server stops working or isn't accessible for whatever reason, please send an email to  (Usually, this is network related -- I just need to restart a reverse ssh tunnel.)  Also, our main reason to run the online demo is to get feedback from users!  If you have comments suggestions or criticisms, please send them to