+**Legacy software** refers to computer systems or applications that are outdated but remain critical to an organization's operations. Though often robust and stable, their underlying [Technology Stack](/wiki/technology_stack) can be difficult to maintain, posing challenges for [Modernization](/wiki/modernization) and integration with newer systems.
+## See also
+- [Technical Debt](/wiki/technical_debt)
+- [Software Maintenance](/wiki/software_maintenance)
+- [System Migration](/wiki/system_migration)