What are legacy applications?
In computing, a legacy application is an outdated method, technology, computerized system, or application program that is still in use. When a system is referenced as a legacy system, it facilitates the standards that follow.
Legacy applications are usually written for outdated operating systems or hardware platforms. An example could be mainframe applications that became legacy apps when the IT industry embraced client/server networks. Another example could be Windows 7 applications running in Windows 8. This means that any proprietary business software that isn’t enabled for the internet can be considered a legacy application.