They released a whole load of stuff.. I think they specialised in documentaries at first with a lot of military/war stuff then got the rights to some Hammers and other British films. Not sure if they went into administration or bust but they have a remnant.
http://www.simplyhe.co.uk/
A lot of their old titles have been going for reasonably big money.
Here's what I can remember off the top of my head
Strangeways
Four-sided Triangle
Abominable Snowman
X-The Unknown
Quatermass Xperiment
Quatermass 2
Frankenstein and the Monster From Hell
Captain Kronos
Night of the Big Heat
Curse Of The Crimson Altar
Blood Beast Terror
Creeping Flesh
Island of Terror
Devil's Men
Revenge
Think there's more. Definitely a Hammer noir/crime film at least