The Yahoo Widget Engine (Konfabulator) has a very flexible application programming interface (API) based on JavaScript with many features useful to developers. A few basic features include items such as text-areas, images, and timers. Other features include the ability to download webpages from the Internet, as well as file input/output, and animator objects to aid in visual effects. A built in interface allows widget developers to run OS specific code such as shell scripts and COM applications on Windows, and AppleScript on Mac.