The super-serum

Leaving aside the fact that the Winter Soldier (who was, basically, a ghost) didn’t disable the camera before killing the Starks, there is a bigger question at hand: did Howard Stark develop the super-serum on his own? And, if so, did he intend to create some other super soldiers?
Or was it something else?
As I understand it, it wasn’t exactly the serum used on Steve Rogers, but rather the result of another attempt to recreate it. The reason for this belief is that the soldiers it has enhanced seem pretty unstable from a psychological point of view. They were, to some degree, in the same state as Emil Blonsky.
If I’m right, is this another connection to the Incredible Hulk? And if it is, can we expect the serum to pop up in other movies, as well?
Next, Hawkeye and Sharon Carter…
