Abstract: Business rules may be harvested from software using automated processes and used in developing new computer software. Automated harvesting may speed up development, reduce cost, and decrease human error during software development. Harvesting the business rules from computer software may also allow business analysts to verify and update business rules. The business rules may be harvested by parsing existing source code into abstract syntax trees (ASTs). The source ASTs may then be transformed into target ASTs corresponding to a programming language different from the existing source code. Those target ASTs may then be recomposed into output source code of the different programming language.