| Business | Phone |
| Cartography & Geographic Info 6 Montgomery Village Ave, Gaithersburg 20879 | (240) 632-9522 |
| Potomac Information Systems 18943 Bonanza Way, Gaithersburg 20879 | (301) 216-2655 |
| Geographic & Land Info Society 6 Montgomery Village Ave, Gaithersburg 20879 | (240) 632-9700 |
| Infoscan Corp 301 High Gables Dr, Gaithersburg 20878 | (301) 519-0050 |