For languages with significant inflectional morphology, development of a morphological parser is often a prerequisite to further computational linguistic capabilities. We focus on two difficulties for this development: the short lifetime of software such as parsing engines, and the difficulty of porting grammars to new parsing engines. We describe a methodology we have developed to promote portability, using a formal declarative grammar written in XML, which we supplement with a traditional descriptive grammar. The two grammars are combined into a single document using Literate Programming. The formal grammar is designed to be independent of a particular parsing engine’s programming language, thus helping solve the software lifetime and portability problems.