These instructions are current as of 06 Feb 2013.
PAE - Most trades positions (44K PDF)
GHG - Computer, communications and networking support (1.6M PDF)
GSC - Food and janitorial services (136K PDF)
Lockheed Martin - Managerial and science support (618K pdf)
SecureInfo - Infosec support (466K PDF)
UTMB - Medical support (5.7K PDF)
Not listed above: Damco (shipping, freight and logistics) and Best Recycling (solid waste handling) also hire for the ASC.