Hortonworks Release engineering team hosts all the released HDP maven artifacts at http://repo.hortonworks.com/content/repositories/releases/.

Other than the release artifacts, there are certain third party artifacts that are necessary for building the HDP stack which are hosted in the Hortonworks nexus repository as well at:

http://repo.hortonworks.com/content/repositories/jetty-hadoop/

and

http://repo.hortonworks.com/content/repositories/re-hosted/

If a developer wants to develop an application against the HDP stack, and they also have a Maven repository manager in-house, then they could proxy these three repositories and continue referring to his/her internal maven groups repo.

If the developer does not have access to his in-house maven repo, they can directly use the Hortonworks public groups repo at: http://repo.hortonworks.com/content/groups/public/and continue developing applications.