Definition - What does Legacy Application mean?
A legacy application is a software application that is considered obsolete, or that is based on technology that is older than a current standard.
Techopedia explains Legacy Application
The term "legacy technology" can refer to applications, platforms, hardware setups, programming languages and other technologies that have been superseded by newer options. That said, much discussion around legacy applications and legacy technology revolves around updating what is used by a particular end user or enterprise client.
Experts often discuss legacy application or legacy system migration, which involves migrating data and tools from older technologies to newer ones. The degree of difficulty depends largely on how both the older systems and the newer systems were built—whether they were built with the capacity for easy updates and migration.
One example of legacy system migration—and one that impacts legacy application migration—is the use of newer operating systems. As device operating systems evolve rapidly, older versions are always becoming obsolete. Users and technology managers have to worry about how to constantly migrate applications and data up through successive versions of operating systems. This may be easy in some ways, but difficult or nearly impossible in others. Migration can be extremely labor intensive, and it can require the transmission of data one bit or element at a time.
Migration of legacy applications and legacy systems is critically important in enterprise IT management. Companies have to assess the cost of migration and how to do it effectively. They have to identify legacy systems and evaluate legacy applications and legacy technology to see if it really is obsolete or if it can stay in place for the short term. This is one responsibility of overall IT planners such as chief information officers and others involved in executive-level planning.