I am pleased to announce version 0.3 of the package level-monad. This package implements breadth-first search directly as an instance of MonadPlus (without using an intermediate tree representation). In version 0.3 I have added a MonadPlus instance for iterative deepening inspired by Michael Spivey's paper on "Algebras for combinatorial search"[1]. The package is on Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/level-monad Sources are on Github: http://github.com/sebfisch/level-monad Cheers, Sebastian [1]: http://spivey.oriel.ox.ac.uk/mike/search-jfp.pdf