The process of writing large parallel programs is complicated by the need to specify both the parallel behaviour of the program and the algorithm that is to be used to compute its result.
What should you learn first, Lisp or Haskell? It depends entirely on your personality. One thing is certain - if you want to be a great developer eventually you'll have to learn both.
citeproc-hs is a library for automatically formatting bibliographic reference citations into a variety of styles using a macro language called Citation Style Language (CSL).