| Business | Phone |
| Concurrent Systems Inc 25541 S Klemme Rd, Crete 60417 | (708) 672-1700 |
| Egm Communications 3695 Edward Dr, Crete 60417 | (708) 367-0276 |
| Leading Edge Provider 3115 E Poplar Ln, Crete 60417 | (708) 367-0851 |
| Quality Computer Systems Crete 60417 | (708) 672-3915 |