Hakyll 3 is mostly inspired by nanoc. The key differences between nanoc and Hakyll are:
* type-safety of Haskell prevents you from doing I/O where this could be dangerous;
* while nanoc layouts can contain code (erb), Hakyll templates do not support this -- all code needs to go in the Haskell configuration file;
* Hakyll uses pandoc for document reading/conversion, nanoc usually uses kramdown and other ruby libraries;
* Nanoc uses a separate DSL for "routes" and "compilation rules", in Hakyll these are defined in the same DSL;
A more in-depth comparison would indeed by very handy. The author of nanoc lives near me, so I'll see if we can come up with a decent comparison together.
