Humor, a reversible, string-based unification approach for lemmatizing and disambiguating language data, has been used for both language corpus analysis and creation of a variety of linguistic software applications such as spell-checking. The system is language-independent, allowing multilingual applications for a variety of language types. Its Hungarian version, the largest and most precise implementation, contains nearly 100,000 stems. The system has been tested rigorously by both linguists and end-users of word-processing tools. Humor-based linguistic modules have been licensed by major software producers, and the lemmatizer has been used in lexicographic research since 1991. One tool provides disambiguation, tagging, and parsing functions. The system can describe various natural languages, including both Eastern European and non-Eastern European languages. Several Humor subsystems for different purposes (lemmatizing, hyphenating, spell-checking/correcting, grammar checking) are commercially available, and have been built into several major word-processing and full-text retrieval systems. An inflectional thesaurus and a series of intelligent bilingual dictionaries have also been developed. (MSE)