Ok, I think, I made it right now. I wrote two versions of the very same module with roughly the same interface. It is minimalistic framework for producing, transforming, zipping and folding streaming data (a sample code that does file IO provided, but it is not well tested yet). One version abuses CPS-style, requires rank2types, but should be slightly faster and has cleaner code. Other version is plain haskell-98 and should be reasonable portable, but is tricky at some plases and still uses CPS for specifing stream processors. I want to add many things, but currently I want to document code properly so it be easy to read (BTW, has someone any article, produced from *.lhs with good typesetting and with *.lhs itself avaible? ) current links https://github.com/permeakra/Rank2Iteratee https://github.com/permeakra/PassiveIteratee The main difference from 'original' iteratees I read about is that both do not use 'chunks' and pass data one-by-one. So, what I wrote may be slower, but should be easier to maintain and more transparent for ghc optimising facilities. I wanted as clean and simple code as possible, but it is still very, very messy at some places and I want it cleaner. Any suggestions? I also want to check, how good ghc does its work with this messy modules. They may become interesting benchmarks.