Roger López (aka zroger) talks about the Chaos tool suite, or more commonly referred to as "ctools." This suite of tools were originally developed by Earl "merlinofchaos" Miles to contain a number of APIs that improve the developer experience. López talks about some of the features such as object caching, plugins, exportables, modal dialog, and the Ajax responder functionality, which was used to build out the new Ajax framework in Drupal 7. Some of the other related modules mentioned are strongarm, features, panels and Views.

For more information, be sure to check out López's DrupalCon presentation called "Leveraging the Chaos tool suite for module development"