Salesforce.com Custom Metadata Types are around for over 2 years. If you are a Salesforce.com ISV and still not using Custom Metadata Types in your apps – you must consider the same.
What are Salesforce.com Custom Metadata Types?
Salesforce.com Custom Metadata Types are similar to custom settings (sometimes confused with them) – but they store the custom metadata instead of data. The advantage is that you can deploy them to production from a sandbox using change sets or as an ISV you can package them with your product.