FLIC, a Fortran loop and index converter, is a parser-based source translation tool that automates the conversion of program loops and array indices for distributed-memory parallel computers. This conversion is important in the implementation of gridded models on distributed memory because it allows for decomposition and shrinking of model data structures. FLIC does not provide the parallel services itself, but rather provides an automated and transparent mapping of the source code to calls or directives of the user's choice of run-time systems or p arallel libraries. The amount of user-supplied input required by FLIC to direct the conversion is small enough to fit as command line arguments for the tool. The tool requires no additional statements, comments, or directives in the source code, thus avoiding the pervasiveness and intrusiveness imposed by directives-based preprocessors and parallelizing compilers. FLIC is lightweight and suitable for use as a precompiler and facilitates a same-source approach to operability on diverse computer architectures. FLIC is targeted to new or existing applications that employ regular gridded domains, such as weather models, that will be parallelized by data-domain decomposition.