Package VS third party VS modules

[eluser]WebMada[/eluser]
Thanks for these answers! Ok I think I understand third_party now: third_party = packages, it's just a set of library+helper+core+config!

HMVC is another story, it is a set of model+view+controller?

Some Codeigniter-built CMS (PyroCMS, openblog, ionize, etc.) all use HMVC, is there a codeigniter common library to implement HMVC?