Access is free, and unlimited. Articles are peer-reviewed. Code is browsable and downloadable as well, as are the data used in the article. Each article comes with a database in which readers can leave comments, and authors can leave responses.
Some articles come with interactive demos.
All these functions can be accessed from the articles homepage. JSS maintains a chatroom on the WWW, used for discussion of statistical software. There is also an archive of documented and reviewed data, basically a subsection of the journal. These functions can be accessed from the journals homepage. There are currently two articles published, and a number under review.