Calling Haskell from...

[Alex Ferguson]

What's the state of the art as regards calling Haskell functions from
'the outside world'?  I note that Haskell Direct has this in its
manifesto, but says "currently unsupported".  Does that mean a moderate
size black hole at the centre of something still potentially usable,
or nothing much at all?

Sorry if this is an 'RTFM' matter, just not sure at present precisely
which 'FM'.

Cheers,
Alex.