This is the WebHCat Manual (also known as Templeton). It will include all WebHCat chapters from the HCatalog 0.5.0 documentation (updated where appropriate) as soon as they can be converted to wiki format. In the meantime, links are provided to the WebHCat chapters for HCatalog 0.5.0 on the Hive site.
WebHCat is the REST API for HCatalog, a table and storage management layer for Hadoop.
Also see the HCatalog Manual for general HCatalog documentation.