| Stephen Hartley Computing | Tapes | No tapes | No books | No hardware |
| S. Morris | No tapes | No tapes | No books | No hardware |
| SR Software | No tapes | No tapes | No books | No hardware |
| S. Taylor | No tapes | No tapes | No books | No hardware |
| Sanderson Software | No tapes | No tapes | No books | No hardware |
| Scisoft | Tapes | No tapes | No books | No hardware |
| Scorpio Research | No tapes | No tapes | No books | No hardware |
| Second Foundation | No tapes | No tapes | No books | No hardware |
| Serious Software | No tapes | No tapes | No books | No hardware |
| Shiva Publishing | No tapes | No tapes | Books | No hardware |
| Sigma Technical Press | No tapes | No tapes | Books | No hardware |
| Silicon Tricks | Tapes | No tapes | No books | No hardware |
| Silversoft | Tapes | Tapes sorted by code | No books | No hardware |
| Simon W. Hessel | No tapes | No tapes | No books | No hardware |
| Simpson Software | No tapes | No tapes | No books | No hardware |
| Sinclair Research | Tapes | Tapes sorted by code | Books | Hardware |
| Sinclair User | Tapes | No tapes | No books | No hardware |
| Softest | No tapes | No tapes | No books | No hardware |
| Softouch | No tapes | No tapes | No books | No hardware |
| Softrax | No tapes | No tapes | No books | No hardware |
| Softsync | Tapes | Tapes sorted by code | No books | No hardware |
| Software Farm | Tapes | Tapes sorted by code | No books | No hardware |
| Software Masters | No tapes | No tapes | No books | No hardware |
| Solent Software Engineering | No tapes | No tapes | No books | No hardware |
| Sprites | No tapes | No tapes | No books | No hardware |
| Stonechip Electronics | No tapes | No tapes | No books | Hardware |
| Stripeland | No tapes | No tapes | No books | No hardware |
| Synacroop Software | No tapes | No tapes | No books | No hardware |