| Business | Phone |
| Aspen Technology 38w548 Barb Hill Dr, St Charles 60175 | (630) 513-7588 |
| Digiploy 41w627 Barberry Ln, St Charles 60175 | (630) 587-3201 |
| Phamis Inc 38w674 Forest Glen Ct, St Charles 60175 | (630) 513-0349 |
| Pacesetter Communication Systs 37w991 Oak Dr, St Charles 60175 | (630) 377-8811 |
| Fine Ground Networks 2020 Dean St, St Charles 60174 | (773) 444-5059 |
| Jvc Magnetics 1905 Fairfax Rd, St Charles 60174 | (630) 443-6350 |
| Impact Technology Resources 814 Steeplechase Ct, St Charles 60174 | (630) 762-9800 |