| .VPB | Unknown Developer | Pliki z grafiką rasterową | Quantel VPB Image Format | Unknown Software | Unknown Developer |
| .VQE | Yamaha Corporation | Pliki audio | Yamaha Sound-VQ Locator File | Unknown Software | Unknown Developer |
| .VQL | Yamaha Corporation | Pliki audio | Yamaha Sound-VQ Locator File | Unknown Software | Unknown Developer |
| .VRA | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .VSR | Microsoft Corporation | Pliki z bazami danych | Microsoft Access Report | Unknown Software | Unknown Developer |
| .VT | Unknown Developer | Pliki z danymi | VT100 Terminal Data File | Unknown Software | Unknown Developer |
| .VUX | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .VXX | Unknown Developer | Pliki systemowe | IOsubsys | Unknown Software | Unknown Developer |
| .VYB | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .W2F | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .W73 | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .WC4 | Unknown Developer | Nietypowe Pliki | WinCheckIt4 Settings File | Unknown Software | Unknown Developer |
| .WEBARCHIV | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .WEI | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .WF2 | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .WINDOWSLIV | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .WINDOWSMED | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .WLF | Microsoft Corporation | Pliki z danymi | Microsoft Windows 98/Me Dr. Watson Log | Unknown Software | Unknown Developer |
| .WLO | JinKe Electronic Company | Pliki eBook | WOLF eBook | Unknown Software | Unknown Developer |
| .WLT | Unknown Developer | Pliki graficzny | WaveL Wavelet Compressed Graphic | Unknown Software | Unknown Developer |
| .WMH | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .WMO | World Meteorological Organization | Pliki z danymi | WMO Binary Format File | Unknown Software | Unknown Developer |
| .WSQ | UTAU Team | Pliki audio | UTAU File | Unknown Software | Unknown Developer |
| .WS_ | Unknown Developer | Pliki konfiguracyjne | Visc15 Adressen Setup File | Unknown Software | Unknown Developer |
| .WVT | Unknown Developer | Pliki z danymi | Compuwx Export Data | Unknown Software | Unknown Developer |
| .WWZ | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .WXW | WiNRADiO | Nietypowe Pliki | WiNRADiO Extended Wave File | Unknown Software | Unknown Developer |
| .X23 | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .X2M | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .X33 | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .X3M | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .XACT | XactSystems | Nietypowe Pliki | XactScript File | Unknown Software | Unknown Developer |
| .XAD | Riven the Mage | Pliki audio | eXotic ADlib Sound Format File | Unknown Software | Unknown Developer |
| .XAK | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .XB~ | Unknown Developer | Nietypowe Pliki | IC File | Unknown Software | Unknown Developer |
| .XCK | Unknown Developer | Pliki z danymi | Extended Crack File | Unknown Software | Unknown Developer |
| .XD | Unknown Developer | Pliki z danymi | CCS-lib.2 Examples Motif-CC File | Unknown Software | Unknown Developer |
| .XDE | Unknown Developer | Pliki z obrazami 3D | Tgif-3.0 File | Unknown Software | Unknown Developer |
| .XDSL | D-Link Corporation | Pliki systemowe | D-link Router UK Firmware Update File | Unknown Software | Unknown Developer |
| .XED | Unknown Developer | Pliki z danymi | XED Chemical Modeler Input/Output Data | Unknown Software | Unknown Developer |
| .XI1 | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .XLTD | Unknown Developer | Nietypowe Pliki | Thunder Temporary Data File | Unknown Software | Unknown Developer |
| .XMAS | Apple | Pliki z danymi | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .XMIT | IBM | Pliki z danymi | IBM XMIT Data | Unknown Software | Unknown Developer |
| .XNX | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .XOS | Xaos Tools | Pliki z grafiką rasterową | Xaos Tools Bitmap Image | Unknown Software | Unknown Developer |
| .XPE | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .XPN | Quest Software | Nietypowe Pliki | Quest Saved Explain Plan | Unknown Software | Unknown Developer |
| .XSEND | Apple | Pliki z danymi | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .XT* | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .XTE | PerkinElmer | Pliki z danymi | LabChip XTe Data | Unknown Software | Unknown Developer |
| .XUP | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .XVID-TRL | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .XWF | Nuance | Nietypowe Pliki | OmniPage Workflow File | Unknown Software | Unknown Developer |
| .XWT | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .XXC | CentraLine | Pliki z danymi | Centraline COACH Controller Firmware | Unknown Software | Unknown Developer |
| .XXX | BloodDolly | Zaszyfrowany plik | TeslaCrypt 3.0 Ransomware Encrypted File | Unknown Software | Unknown Developer |
| .XXXX | Apple | Pliki z danymi | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .XXZ | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .XZP | Unknown Developer | Pliki z danymi | XZP Container Format | Unknown Software | Unknown Developer |
| .YAD | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YAR | Unknown Developer | Pliki skompresowane | YAK Compressed Archive | Unknown Software | Unknown Developer |
| .YC | Unknown Developer | Pliki skompresowane | YAC Compressed Archive | Unknown Software | Unknown Developer |
| .YIN | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YJF | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .YKI | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .YLM | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YN | Unknown Developer | Pliki skompresowane | Audio Utility Tuningwrench Compressed File | Unknown Software | Unknown Developer |
| .YNM | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YNX | Unknown Developer | Pliki audio | Segmax Seqprest Compressed File | Unknown Software | Unknown Developer |
| .YRA | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .YTS | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YUF | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .YYC | Unknown Developer | Pliki z danymi | Wave Sapphire Distribution File | Unknown Software | Unknown Developer |
| .YZF | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZAE | Unknown Developer | Pliki z danymi | ZAwinEHE Project | Unknown Software | Unknown Developer |
| .ZAL | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZAX | Zaxcom | Pliki audio | Zaxcom Audio Data | Unknown Software | Unknown Developer |
| .ZBJ | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZBX | Unknown Developer | Nietypowe Pliki | Disk Volume Identification | Unknown Software | Unknown Developer |
| .ZCH | Unknown Developer | Nietypowe Pliki | ZIG Game Construction Kit Data | Unknown Software | Unknown Developer |
| .ZDB | Synacor Inc. | Pliki z danymi | Zimbra Database File | Unknown Software | Unknown Developer |
| .ZDE | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZDF | Unknown Developer | Pliki z danymi | Zone Definition File | Unknown Software | Unknown Developer |
| .ZDI | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZEB | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZET | Unknown Developer | Pliki skompresowane | ZET Compressed Archive | Unknown Software | Unknown Developer |
| .ZFSENDTOTA | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZGZ | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZH3 | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZIQ | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZONE | Apple | Pliki z danymi | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .ZPAR | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZPKG | Zyxel Communications | Pliki wykonywalne | Zyxel NSA-32x Application Package | Unknown Software | Unknown Developer |
| .ZR4 | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZUC | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
| .ZUN | Unknown Developer | Nietypowe Pliki | Recogsp File | Unknown Software | Unknown Developer |
| .ZVQ | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .ZXF | Unknown Developer | Nietypowe Pliki | Uncommon File Extension | Unknown Software | Unknown Developer |
| .Z•À_•À_P | Unknown Developer | Nietypowe Pliki | Unknown File Type | Unknown Software | Unknown Developer |
z 13 
