DOORS Extension Language (DXL) is a scripting language used to extend the functionality of IBM's ERM DOORS. This programming language is somewhat similar to C and C++. This language is specific to DOORS, and it has its own syntax, declaration, a forum to discuss the development, in addition to the specific reference manuals. DXL scripts were utilized to help the users of DOORS. Much of the native DOORS GUI is written in DXL.