| z3l | ZW3D Part Library |
| z4 | Z-machine Z-code File |
| z5 | Z-machine Z-code File |
| z6 | Z-machine Z-code File |
| z64 | N64 ROM Image Mr. Backup Z64 |
| z7 | Z-machine Z-code File |
| z8 | Z-machine Z-code File |
| z80 | ZX Spectrum Emulator Snapshot Z80 |
| zak | Carlson Survey Coordinate Data |
| zam | ZTreeWin ZTreeWin Application Menu Data |
| zapc | ArcSoft Print Creations |
| zar | Zemax Archive |
| zargo | ArgoUML Model Data |
| zav | MT-Card Saved Game Data |
| zbb | Zemax Black Box Data |
| zbd | Canon ZoomBrowser EX Database |
| zbf | Radiance Z-buffer File |
| zbf | Zemax Beam File |
| zbin | Report Server Localization Data |
| zbp | Boardmaker Compressed Package |
| zcast | Creative ZENcast Organizer Data |
| zch | ZIG Game Construction Kit Data |
| zcode | Z-Suite Code |
| zcr | ZenCrack Data |
| zcv | Zortech 3 Tools Readme Document |
| zda | GP32 ZDA Compressed Archive |
| zdb | NEPLAN Network Topology Data |
| zdb | Zimbra Database |
| zdc | CD Catalog Expert Database |
| zdct | Adobe Localization Dictionary |
| zdm | SIPINA Zlib Compressed FDM Data |
| zdt | Zhongwen Development Tool Data |
| zec | Zemax Encrypted Coating File |
| zen | Zemax Face Number File |
| zfo | 602XML Form Filler Data |