К вопросу о том, что хаскель не нужен и это инструмент для гиков-энтузиастов и никто его в продакшене в здравом уме использовать не будет

Haskell in the Large
(доклад товарища Don Stewart на Google Tech Talk)

http://code.haskell.org/~dons/talks/dons-google-2015-01-27.pdf

пара цитат для затравки:

• Total Haskell code base: >2M lines, >150 contributors (~20 core), >110k commits.
• Haskell code everywhere: real time pricing, risk management, data analysis, regulatory systems, desktop and web GUIs, web services, algo pricing, end-user scripting, and as plugins to C++, Java, C#, Excel.
• Windows, Linux, clusters and grids. On servers and desktops in >30 countries.

GUIs: Generate native Windows WPF GUI or JavaScript app from single Haskell impl.
Bindings: Tons of bindings to external services. Haskell as API glue.

In-house Haskell compiler: `Mu’. One of Lennart’s many Haskell compilers.
• Whole world optimizing compiler.
• Compiles to portable bytecode – same blob runs on Linux or Windows.
• Values, closures, functions can be serialized.

ЗЫ Будем надеяться, что видео тоже выложат

You will always get what you always got
  If you always do  what you always did