Hello, Suppose I have two projects: 1) one that defines a monad transformer and an accompanying type class that captures my monad-specific operations and 2) one that uses the other project, combining the monad transformer with, say, Parsec. Now while writing my Parsec parser I want to use my monad transformer operations without using lift: I need an instance MyMonadT Parsec. Where should this instance go? I can think of three answers, all unsatisfactory: 1) For obvious reasons it shouldn't go in the Parsec package. 2) For pretty much the same reasons it shouldn't go in my monad transformer package, either. Also, it is undesirable to add a dependency on Parsec just for this instance, and the package should not have to know about the projects that are going to use it. 3) If I put it in the second project it is an orphan instance, which is undesirable for well-known reasons. What is the best solution? Thank you, Martijn.