For anyone who has read any of my blog posts from the last couple years and tried to run the code unsuccessfully, this is my fault. I didn’t include proper cabal files with each program to ensure that you had the right versions of the libraries they depend on when you try to build them. As such, nothing is there to stop you from unsuccessfully attempting to build them against the latest and greatest library versions on Hackage, a few of which have changed in API-incompatible ways. This will be repaired in the not-too-distant future. In the meantime, the safest way to make sure they build is to look at the blog posting date, and install the version of the library from hackage that was current around that time. As far as I know, the only major problem dependency is the Gloss visualization library which underwent a few minor API changes that broke a number of my examples.