All Mid-Atlantic companies in ComputerWorld's Top 100 can be seen here.
The three that are based in Philadelphia are:
#8.) The University of Pennsylvania (43 current openings in IT)
#67.) Temple University (14 current IT-related openings)
#90.) Aramark Corp (4 IT-related openings in PA)
Just outside Philadelphia, in Valley Forge, The Vanguard Group Inc. was listed at #60. There are more than 70 open positions on their Caree Search page with a handful of them being IT-related.