| Main Street ROI | New York |
| Main Street SEO in CT | Connecticut |
| Main Street Software, Inc. | Oregon |
| Main Street Softworks, Inc. | Florida |
| Main Street Ventures | Ohio |
| Main Strike | New York |
| MainBloq | New Jersey |
| Mainboard | New York |
| Maine Accelerates Growth | Maine |
| Maine Angels | Maine |
| Maine Center for Entrepreneurs | Maine |
| Maine Geeks, LLC | Maine |
| Maine Graphics | Maine |
| Maine Hosting Solutions | Maine |
| Maine Macintosh Owners & Operators Society | Maine |
| Maine Startups Insider | Maine |
| Maine Technology Group | Maine |
| Maine Technology Institute | Maine |
| Maine Total Technology | Maine |
| Maine's Tech Hub | |
| Mainely SEO | Maine |
| Mainfirst | |
| Mainframe Computer, Inc. | |
| Mainivent Advertising | |
| Mainline Information Systems, Inc. | Florida |
| Mainline Media, LLC | Pennsylvania |
| Mainline.GG, LLC | Texas |
| MainNerve | Colorado |
| Mainpine, Inc. | Oregon |
| Mainsail Partners | California |
| Mainsat Telecommunications International | Florida |
| MainSpring, Inc. | Maryland |
| Mainstack | |
| Mainstack Social Commerce, Inc. | Texas |
| Mainstay | |
| Mainstay Software Corporation | Colorado |
| Mainstay Technologies | New Hampshire |
| Mainstream Computer & Appliance Center | Michigan |
| Mainstream Data | |
| Mainstream Technologies, Inc. | Arkansas |
| MainStreaming | California |
| Mainstreet Computers, LLC | Michigan |
| Mainstreet Systems & Software, Inc. | Pennsylvania |
| MainStreet Work, Inc. | California |
| Mainstreethost | New York |
| Maintainly | California |
| MaintainX | California |
| Maintech, Inc. | New Jersey |
| Maintenance Strategies, Inc. | Pennsylvania |
| MainTree Systems | Tennessee |