multiarg is a parser combinator library to build command line parsers. With it you can easily create parsers with options that take more than one option argument--for example, I created multiarg due to the apparent lack of such ability amongst other parsers. Its basic design is loosely inspired by Parsec. Provides ParserT, a monad you use to build parsers. ParserT is a monad transformer, so you can layer it on top of other monads. For instance you could layer it on the IO monad so that your parser can perform IO. It also has a simple, pre-built parser built with the underlying combinators, which works for many situtations and shields you from the underlying complexity if you don't need it. Any feedback you might have is much appreciated. You can email or fork it on github. The Haddock comments are extensive so those should be able to get you started. multiarg on Hackage: http://hackage.haskell.org/package/multiarg multiarg's git repository: https://github.com/massysett/multiarg