== Inclusion criteria == 
 I've been struggling with determining exactly how to evaluate companies to put on this list.  My working criteria for inclusion are listed below: 

 === Eligibility === 
 * Must be within the "Delaware Valley" Census designated place.   
 ** Including: Phila, Wilmington, Camden, Reading (new for most recent CDP def.) 
 ** Not including: Atlantic City, Trenton, Harrisburg, Lehigh valley 
 * Law firms and other professional partnerships are eligible. 
 * Local companies that were acquired by non-local companies are eligble. (PECO, SmithKline) 
 * Companies of the past like PRR and Reading are eligible. 
 * Government agencies like PGW and PWD are not eligible. 
 * Non-profit agencies like IBX are not eligible, despite being incorporated. 

 === Notability === 
 Specifying notability requirements is harder.  Special attention will be paid to headquarters within Philadelphia.  I'm just throwing out numbers here: 
 * Fortune 1000 members certainly included. 
 * Companies with over $100M annual revenue included. 
 * Companies with more than 250 employees included. 
 * Phila based companies with over $25M annual revenue considered. 
 * Phila based companies with more than 100 employees considered. 
 * Well known consumer brands should be included.  Public knowledge may be primarily in the DelVal area. 
 * Companies with buildings named after them are notable and should be mentioned no matter what their current status is.