What is the best usage of haskell in terms of build-in capabilities or external libraries?

[Peng Yu]

Hi,

When a language is selected for a project, a practical matter is what
the language provides.

For example, if I need to use regex a lot, I probably want to use perl
rather than other languages, because perl is the best in terms of
regex and have much influence on other languages that have support on
regex. If I need to do a lot of statistics, I'd better use R, because
there are already a lot of statical packages implemented in R. And if
there is a statistical method, it is most likely to implemented in R
first. If I want to implement matrix numerical algorithm, I'd better
use Fortran.

After reading some wiki pages of haskell, it is not clear to what area
haskell is really good for. One strong point seems to be a testbed for
trying new languages. But this seems to be the case for other
functional languages as well.

Is there an application area in which haskell is much stronger than
other different languages?

-- 
Regards,
Peng