Download, what for?
As the game is available online, it's not strictly necessary to download it to play. And should you wish to access source code, the "view source" and "save as" fonctions of your web browser should be enough. However, as it is Free Software, you can of course download the source code in a package, which contains a copy of the GPL for instance. Happy hacking!
FYI, all releases are available online, and it's possible to play them.