Following HCatalog's merge with Hive (in March of 2013) HCatalog is now released as part of Hive. Older versions of HCatalog can still be separately downloaded.
Old releases may be downloaded from Apache mirrors:
This release introduces webhcat (a web services API to HCatalog), artifacts published in the maven central repository, and many improvements and bug fixes. Release Notes are available at the download site.
This release adds support for reading and writing from Hive, switches HCatalog to use Hive's SerDe interface instead of HCatalog specific StorageDescriptors, and adds experimental support for HBase. Release Notes are available at the download site
This is a first release of Apache HCatalog. Release Notes are available at the download site