Others have mentioned excellent software like pandoc and xmonad. There are also projects with a smaller target audience, but that are insanely impressive compared to what you could plausibly do in basically any other language. In particular, I've used Clash and Lambda-CCC, which let you compile Haskell code to VHDL or Verilog and put it on an FPGA.
I think the number of useful tools is pretty closely correlated to popularity, and obviously Haskell has a relatively small user base. It's not like Haskell gives you super-powers and makes you 10x more productive; it mostly lets you write better software, not necessarily more software. I do feel more productive with Haskell, but it's on the order of 50-100% (depending on the task), not enough to let Haskellers match the open-source output of a very popular language like C.
I think the number of useful tools is pretty closely correlated to popularity, and obviously Haskell has a relatively small user base. It's not like Haskell gives you super-powers and makes you 10x more productive; it mostly lets you write better software, not necessarily more software. I do feel more productive with Haskell, but it's on the order of 50-100% (depending on the task), not enough to let Haskellers match the open-source output of a very popular language like C.