| xyz | RPG Maker Graphic Data |
| y | Yacc Source |
| yab | Yabasic Source Code |
| yac | Yacc Source |
| yacc | Yacc Source |
| yajl | YAJL Script |
| yang | YumaPro YANG Module |
| yaws | Yaws Server Dynamic Page |
| ygl | YAGL Script |
| yin | YumaPro YIN Module |
| yml2 | YML 2 Script |
| ymx | Yukes 3D Object |
| yo | Y86 Assembler Object |
| yobj | Yukes 3D Object |
| ypp | GNU Bison Source Code |
| ys | Y86 Assembler Source Code |
| ysp | BYOB Sprite |
| yxx | GNU Bison Source Code |
| yy | GNU Bison Parser |
| z | Zero Compiler Header |
| zanebug | Zanebug Data |
| zasm | Zero Compiler Assembly Source Code |
| zbi | Zeus IDE Special Tags Data |
| zbj | Visual Zero Object |
| zbl | Zeble Markup Data |
| zcls | Zero Compiler Class Data |
| zcos | Scilab XML Diagram |
| zef | Unity Pro Full Application Exchange Data |
| zem | Zope External Editor File |
| zep | Zephir Source Code |
| zepto | Zepto JS Script |
| zexp | Zope Binary Export File |
| zf3d | Flare3D Model |
| zfd | ABC Zeroadic Functions Data |
| zfrm | Zero Form Designer Data |
| zh | Netscape Navigator Java Classes File |
| zipxml | Xamarin Zipped XML Data |
| zix | Caml Light Debugger Data |
| zodb | Zope Object Database |
| zog | Zoggy Data |
| zp | Zepto Source Code |
| zpd | ABC Zeroadic Predicate Data |
| zpk | Zend Studio Application Package |
| zpl | Zimpl Program Data |
| zpt | Zope Page Template |
| zrf | Zillions Rules |
| zrp | RapidPLUS Application Package |
| zrx | ZOC REXX Script |
| zs | ZenScript File |
| zsc | zMUD Script |
| zsf | Zend Server Exported Events |
| zsh | Z-Shell Script |
| zsm | ZSM Assembler Source Code |
| zsrc | Zero Compiler Source Code |
| ztk | Zope Toolkit Data |
| zts | ZTerm Script |
| zu | Zimbu Source Code |
| zul | ZK User Interface Layout |
| zup | Microsoft Dynamics NAV Development Environment Setup Parameters |
| zw | Zooper Widget Template |
| _bsln140 | Blend for Visual Studio Data |
| _sln100 | Visual Studio Data |
| _sln110 | Visual Studio Data |
| _sln120 | Visual Studio Data |
| _sln130 | Visual Studio Data |
| _sln140 | Visual Studio Data |
| _sln150 | Visual Studio Data |
| ~cp | Borland C++ Builder Source Backup |
| ~de | Borland C++ Builder Project Backup |
| ~df | Delphi Form Backup |
| ~dfm | Delphi Form Backup |
| ~h | Borland C++ Builder Source Backup |
