Search engines like sitemaps. Hakyll doesn't have this ability out of the box, but it is quite trivial to add. Here is my approach.
Combining Haskell and a well-known C library is easy.
apt-get/yum install, link with it, create bindings and we're done. Problems start to emerge when we don't want to, or can't, install the library globally. Things get even worse, when the library uses C++. I faced this problem when writing hlibsass and I think that I've managed to solve it in a not-so-terrible way.
It was a matter of time when I will start my new blog. This time with new brand, completely different backend and with different language. I hope I will persist a little bit longer than last time, but I make no promises here.