| w3l | W3launch Data |
| w44 | dBASE IV Temporary Data |
| w7g | Yamaha Motif ES Arpeggio Data |
| w7s | Yamaha Motif ES Song Data |
| w7w | Yamaha Motif ES Waveform Data |
| w86 | Emacs W86 Data |
| wa! | Tascam Gigastudio Compressed Waveform Data |
| waa | eXtendable Wad Editor WAA Data |
| wab | Windows Address Book Data |
| waflib | Dental Wings Open System Data |
| waj | WinAutomation Job |
| wajac | Sesam GeniE Wave Load Input Data |
| wake | HEADTAIL Wakefield Repository Data |
| wal | CodeWallet Pro 3 Wallet |
| wal | WinAMP Skin |
| wallet | MultiBit Wallet File |
| walletx | Enpass Backup Data |
| wand | GarageBand Magic Template |
| wao | WinAutomation Add-on |
| was | Symantec Procomm Plus Script |
| wavm | eXtendable Wad Editor WAVM Data |
| wax | Procomm Plus Compiled Script |
| wa_ | Compressed WAV File |
| wb4 | WindowBlinds 4 Default Skin |
| wba | WindowBlinds Skin |
| wbb | WinBackup Archive |
| wbc | Webshots Image Collection |
| wbcat | Windows Backup Catalog |
| wbd | eBeam Whiteboard |
| wbd | Softlink Whiteboard |