Eris is a platform for building, testing, maintaining, and operating distributed applications with a blockchain backend.
Eris is not a single blockchain, it is an open source blockchain design and a number of tools which allow you to prototype and build blockchain-based systems. basically, you make your own blockchains with it and add whatever contracts you need to it for your system.
Meet Doug, the Smart Contract Marmot.
Most of the content is taken from Eris website, some of it summarized. The aim is to add practical examples and comparisons, to explain, without oversimplifying, how t use these tools to build your own blockchain based and smart contract based system.
To learn how to build Dapps using Eris and meet the team join Eris Meetup in London