ABAP Development Tools (ADT) is an Eclipse plugin that allows developers to use Eclipse as an integrated development environment (IDE) for ABAP development. ADT integrates multiple development technologies like ABAP, SAPUI5, Java, and HANA in a single environment. It also allows development on Windows, Linux, and Mac operating systems as well as across multiple ABAP systems. The installation of ADT requires prerequisites like Java, Eclipse, and an AS system before it can be configured for use.