Half of it is given to the EXP Share holding Pokemon. The other half is distributed amongst combatants as normal.
(If there are 2 EXP Shares in the party being held, each one of them gets a third, with the final third distributed...and so on, if you have multiple EXP Shares held.)
Thanks for replying.
One more question:
In a double battle, if one pokemon has the Exp Share, it still gets 50%. If the other pokemon makes a kill, does the EXP Share pokemon get an EV, too?