A common problem when revitalizing old scientific software is the need to recreate a working build environment. With standards-conforming code, this is usually straightforward, often a matter of setting a few compiler flags to initialize variables, persistently save local variables, adjust floating point exception-handling, etc. Occasionally one is faced with code that made use of library routines which are not available under the current build environment or which require a software license incompatible with the legacy code’s license. This is especially true of the routines provided with the book Numerical Recipes; back when the book was used as a primary text for numerical analysis, less attention was paid to software licenses and most students (now practicing engineers and developers) were unaware the code from the book was proprietary and could not be redistributed without a commercial license.
The Acorvid Legacy Fortran Compatibility (ALFC) library was created to assist in revitalizing legacy code by providing an open API to a number of proprietary and vendor-specific libraries. At present it contains compatibility interfaces for Numerical Recipes functions (FORTRAN 77 version) and the Sperry-Rand UNIVAC large scale systems libraries, MATH-PACK and STAT-PACK. The ALFC library is licensed under the MIT License which should be permissive enough for almost any application.