| File extension Name |
extension description |
| .5 | IBM Voice Type Language Script Data File |
| .5 | Salt Lake City Game Music File |
| .5 | Screen Log File |
| .5 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .500 | Tally File (Tally Solutions Pvt. Ltd.) |
| .500 | NCBridge NC200/NC400 Series Network Boot Software (Network Computing Devices, Inc.) |
| .500 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .504 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .510 | Cthugha 51 File |
| .512 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .51Z | CropWalker |
| .52 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .520 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .521 | Murray State University Trojan Ring Configuration File |
| .538 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .5445 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .545 | aiMutation AOL Instant Messenger Skin |
| .567 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .586 | Asm586 |
| .58M | Canon i560 Printer Driver Temporary Output (Canon, Inc.) |
| .5A | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .5D | Works File (Microsoft Corporation) |
| .5DK | OS/2 Saved SKF Format File (IBM) |
| .5INFO | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .5OO | DOS7 File |
| .5PS | Manual PS File |
| .5SLRDECREAS | EdGCM Results File (The EdGCM Cooperative Project of Columbia University) |
| .5TH | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |