Understand for FORTRAN is an interactive development environment (IDE) tool providing reverse engineering, automatic documentation, metrics and cross referencing of FORTRAN source code. It supports FORTRAN 77 (F77) and FORTRAN 90 (F9X) language standards, with common VAX, Cray and Salford extensions.
Understand for FORTRAN helps you reverse engineer, understand and maintain large amounts of legacy FORTRAN source code. The tool includes a syntax colorizing "smart" editor that can tell you about what you are editing. It also includes numerous graphical reverse engineering views designed to help you understand and assess changes you are considering in your code.