I've dabbled in haskell, but am by no means an expert. I was hoping someone here could help me settle this debate so that we can more seriously consider haskell for a next version of an application we're building.... I would like to understand better what its capabilities are for directly mapping and managing memory. For instance, I would like mmap many large files into memory and mutate their internals directly... without needing to reallocate them (or chunks of them) in the haskell heap, and without resorting to a byte-array and byte-offset representation. Furthermore, I might also like to map intrinsic haskell data structures into this mmap'd memory such that standard library functions can manipulate them (perhaps in a purely functional way, e.g. treating them as haskell arrays of smaller foreign structures). I understand that the foreign function interface has the ability to marshall/unmarshall C structs, but I'm unsure of the memory implications of using this mechanism. Our application has a very large footprint, and reallocating some or all of these mapped files is a non- starter. Thanks, Warren