Kraken.js is a Node.js framework that provides additional features and tools called "arms" to extend an application's capabilities. These arms include Makara for internationalization, Lusca for security, Adaro for template rendering, and Grunt tasks for testing and compiling LESS. Additional arms like Pine for logging and Nemo for automated testing are also in development as part of PayPal's open source projects. The presentation demonstrated how Kraken.js was used to build the PayPal.me site and provided a code sample for internationalization and template rendering.