This area of the EPICS website provides access to EPICS Base and various Extensions and other Support modules that are maintained at APS. Links to the downloadable files can also be found on the pages associated with each individual item, and beginners are recommended to use those pages, which also provide access to documentation.
EPICS Base is open source software and can be freely downloaded and distributed. You will need to install a copy of EPICS Base to be able to build any of the EPICS Extensions or Support Modules.
The EPICS IOC Support Modules distributed by the APS controls group are available for download from the EPICS Modules area.
The EPICS host tools that distributed by APS are available for download from the EPICS Extensions Download subdirectory.
EPICS Distributions are collections of software used with EPICS.
This area contains/will contain sample and demonstration IOC applications that the APS controls group has developed which are likely to be of more general interest.
The EPICS CVS repository contains some modules, extensions and old versions of Base and is browsable using ViewVC. Most of these projects probably have newer versions available on github though.