There is no content on the MKWS site, just tools:

• mkws.js -- JavaScript code that powers the MasterKey Widget Set
• /libjs-pz2/pz2api.1.js -- Low-level JavaScript library for access to the MasterKey web service.
• mkws-complete.js -- A single large JavaScript file containing everything needed for MKWS to work: the widget-set itself, the API library, and any additional prerequisites such as jQuery.
• mkwsStyle.css -- A stylesheet which styles only MasterKey widgets, and does not otherwise interfere with application-site's styles.

  Note. This is not yet quite true: the stylesheet needs tweaking to make it more specific to only the MKWS components. At present it spills over into styling parts of the containing site, too.

For a very simple application that uses these, see http://somesite.indexdata.com/. It's worth viewing the source to see how small it is. Also on that site a jQuery plugin version with a single line of JavaScript code.

See also the README (which may not be fully up to date).