Depends on what the project is. If parsing is the biggest part of the project then I would say Haskell is top-class in that respect. It has proven success stories. However, due to the lack of control over GC it has latency issues with certain kinds of work and it's not a great choice for writing demanding games.

For me, one of the big holes in the Haskell story is a great, idiomatic GUI toolkit. That makes it a little more difficult to use for standard desktop applications, but not impossible (after all, there are binding to common frameworks like GTK etc).