But with more seriousness, if you are going to make a triple-A game, C++ is most likely the way to go.
Until then, you should use other more sane languages.
Wall sliding is done by moving the colliding object along the collision normal until he stops colliding.
I assume any physics engine gives a collision listener which also feeds the collision "force", which is just the penetration vector's length.
You can use that to apply your own response, but remember to check the normal's direction, or you'll slide down on ramps too.
For some reason I don't understand, no one introduced a window-less OpenGL context, so you have to make a window.
If you don't want it showing, just set it to be hidden.
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