The delite tutorial guides you, step by step, through some of the important concepts in delite as well as introducing you to some more fundamental, core API's.
delite - creating custom components
It can be used on its own but more likely used with other projects either from the ibm-js repositories or other repositories.
More information can be found on the delite website explaining the standards this library aims to conform to.
delitewas written by the same developers who wrote the Dojo Toolkit Dijit framework.