Creating and Modifying Entities
The Entity API and the Entity System in general makes it really easy to deal with entities programatically.
Since ECK is all about Entity types, Bundles and Entities, I guess it would make sense to have some documentation on how to deal with entities programatically. Everything in this section of the documentation assumes that you are using the Entity API contrib module (entity) which is true for anyone using ECK.
The Entity API and the Entity System in general makes it really easy to deal with entities programatically.