| zcx | ZCX File Protector Encrypted Data |
| zda | GP32 ZDA Compressed Archive |
| zdat | Zoom Search Engine Data |
| 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 |
| zdtc | Adobe After Effects Language Settings |
| zec | Zemax Encrypted Coating File |
| zen | Zemax Face Number File |
| zfo | 602XML Form Filler Data |
| zfp | Zoner Photo Studio Exported Presets Data |
| zgraph | L3DT ZeoGraph XML Data |
| zgy | Petrel Compressed Seismic Data |
| zib | ZX-Editor Graphic Library |
| zic | ZooImage Categories Data |
| zid | ZooImage 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 |
| zit | ZIT File Tracking Repository Data |
| zix | Quicken Data |
| zjv | PARTsolutions 3D Model |
| zkn | Adobe RoboHelp WebHelp Skin Definition |
| zks | ZK Stereo Data |
| zktx | libGDX Compressed Texture Data |
| zkx | ZixCorp Signature Data |
| zlb | Form Z Symbol Library File |