| zcx | ZCX File Protector Encrypted Data |
| zda | GP32 ZDA Compressed Archive |
| zdat | Zoom Search Engine Data |
| zdb | Zimbra Database |
| zdb | NEPLAN Network Topology Data |
| zdc | CD Catalog Expert Database |
| zdct | Adobe Localization Dictionary |
| zdm | SIPINA Zlib Compressed FDM Data |
| zdt | Zhongwen Development Tool Data |
| zdtc | Adobe After Effects Language Settings |
| zec | Zemax Encrypted Coating File |
| zen | Zemax Face Number File |
| zeon | VUE Installation Data |
| zfo | 602XML Form Filler Data |
| zfp | Zoner Photo Studio Exported Presets Data |
| zgraph | L3DT ZeoGraph XML Data |
| zgy | Petrel Compressed Seismic Data |
| zh_tw | Netscape Communicator Java Language Classes |
| zib | ZX-Editor Graphic Library |
| zic | ZooImage Categories Data |
| zid | ZooImage Data |
| zig | ZIG Game Construction Kit Game Data |
| zil | DMDX ZIL Output Data |
| zim | OpenZIM Archive |
| zimaa | OpenZIM Splitted Archive |
| zimab | OpenZIM Splitted Archive |
| zimac | OpenZIM Splitted Archive |
| zin | ZINDO Input Data |
| zipo | Need for Madness Game Data |
| zis | ZooImage Series Description |