Paresc is a great piece of software. But there are some things which do bother me occasionally. A short list: Things I'd like to change: a) custom location tracking. (I've already written a patch, but I haven't tested how much speed will suffer? Which would be a nice test?) b) Add a function returning a monadic result (thus either (fail . show) return each time .. ) because I feel like doing this all the time. c) make some functions more generic examples: module Text.ParserCombinators.Parsec.Char (these functions should work with any token type): anyChar -> anyToken char -> expectToken string -> expectTokens satisfy d) export some simple functions such as nat decimal etc.. Sometimes all I just want to get an integer without importing Tokens and specifying a language.. shapr / sorear suggested asking SPJ to contact Daan Leijen. Perhaps there are different approaches to address the issues above? Do you also have some patches / suggestions ? Marc Weber