Why a Object Relational Mapping (ORM) framework is called a Micro ORM but not full featured ORM? Which features and/or non-existent features makes an ORM framework, a Micro ORM? 

I derived following features from my knowledge of Hibernate, NHibernate, Entity Framework. But I would like to learn more about this. A [google search](https://www.google.com/search?aq=f&sugexp=chrome,mod=5&sourceid=chrome&ie=UTF-8&q=what%20is%20micro%20orm) gives a lot of library/framework results but no satisfactory definition of Micro ORM in TOP results.

* Cache
* Second Level Cache
* Inheritance Mapping
* Query Language (HQL, JPAQL etc)
* Different Mapping Strategies
	+ One class per table
	+ ...
* Many-to-One, one-to-one, Many-to-Many mappings
* ...

Is following libraries considered as Micro ORM? why / why not?

* [Data Access Application Block](http://msdn.microsoft.com/en-us/library/ff649538.aspx) in .NET
* [ibatis](http://ibatis.apache.org/)