A legacy application (legacy app) is a software program that is outdated or obsolete. Although a legacy app still works, it may be unstable because of compatibility issues with current operating systems (OSes), browsers and information technology (IT) infrastructures.
Most enterprises use legacy applications and systems that continue to serve critical business needs. Typically, the challenge is to keep the legacy application running, while converting it to newer, more efficient code that makes use of current technology and programming languages.
