| Business | Phone |
| Stargate Communications Inc 2805 Butterfield Rd, Oak Brook 60523 | (630) 572-2242 |
| Audience Audits Intl 1000 Jorie Blvd, Oak Brook 60523 | (630) 990-1613 |
| Interface Software 1420 Kensington Rd 320, Oak Brook 60523 | (630) 572-1400 |
| Janisch Data 1000 Jorie Blvd 24, Oak Brook 60523 | (630) 990-1610 |
| Maintech 2021 Midwest Rd, Oak Brook 60523 | (630) 953-6280 |
| On Line Financial Svc Inc 900 Commerce Dr 203, Oak Brook 60523 | (630) 571-7900 |
| Paramount Business Technology 900 Jorie Blvd, Oak Brook 60523 | (630) 368-1422 |
| Sei Information Technology 1301 W 22nd St, Oak Brook 60523 | (630) 571-4380 |
| Sennett & Assoc Data Prcsng 2625 Butterfield Rd, Oak Brook 60523 | (630) 789-9440 |
| Tilbury Corp 2625 Butterfield Rd, Oak Brook 60523 | (630) 586-9660 |
| Unitrin Data Systems 1 N Tower Rd, Oak Brook 60523 | (630) 368-8000 |