If you previously downloaded either the base system or specialized packages, and intend to download new or updated packages, you should download new versions of both the base system and whatever specialized packages you want. The packages here include the base system, including only a portion of the modules being developed.
Specialized packages are also available.
There are example data files. Developer documentation has been made a separate download to decrease the size of the base system download. You can get it here . Below are the specialized packages currently available. Additional packages may appear here in the near future.