| .S | Unknown Developer | File sviluppatore | Source Code File | Microsoft Notepad | Microsoft Corporation |
| .S19 | Motorola | File sviluppatore | Motorola EEPROM Programming Data | Sublime Text | Sublime HQ Pty Ltd |
| .S43 | IAR Systems | File sviluppatore | IAR Assembly Source | IAR Embedded Workbench | IAR Systems |
| .S4E | GMO Cloud KK | File sviluppatore | Airplay SDK Header File | Marmalade SDK | GMO Cloud KK |
| .SAL | Oracle Corporation | File sviluppatore | SQL Application Language Source Code | MySQL | Oracle Corporation |
| .SANTEM | ifu Hamburg GmbH | File sviluppatore | e!Sankey Template File | e!Sankey | ifu Hamburg GmbH |
| .SAS | SAS Institute Inc. | File sviluppatore | SAS Program File | SAS | SAS Institute Inc. |
| .SASF | NASA | File sviluppatore | NASA Spacecraft Activity Sequence | Unknown Software | Unknown Developer |
| .SAX | Open Source | File sviluppatore | Sedona Framework XML Application | Sedona Framework | Open Source |
| .SB | MIT Media Lab | File sviluppatore | Scratch Project File | MIT Scratch | MIT Media Lab |
| .SB2 | MIT Media Lab | File sviluppatore | Scratch 2.0 Project File | MIT Scratch | MIT Media Lab |
| .SB5 | Lindersoft | File sviluppatore | SetupBuilder 5 Installation Script | SetupBuilder | Lindersoft |
| .SBI | Creative Technology Ltd. | File sviluppatore | Sound Blaster Instrument | Virtual Sound Blaster | Creative Technology Ltd. |
| .SBR | Microsoft Corporation | File sviluppatore | Visual Studio Source Browser Intermediate File | Microsoft Visual Studio | Microsoft Corporation |
| .SC | Vladimir Romanyuk | File sviluppatore | Space Engine Script | Space Engine | Vladimir Romanyuk |
| .SCALA | Scala | File sviluppatore | Scala Source Code File | Scala IDE for Eclipse | Scala |
| .SCC | Microsoft Corporation | File sviluppatore | SourceSafe Source Code Control File | Microsoft Visual Studio | Microsoft Corporation |
| .SCX | RIX SoftWorks, Inc. | File sviluppatore | ColoRIX Bitmap Graphic File | XnView MP | XnSoft |
| .SDEF | Apple | File sviluppatore | AppleScript Dictionary Document | Apple Xcode | Apple |
| .SDI | Intuit, Inc. | File sviluppatore | QuickBooks Data File | Intuit QuickBooks Pro | Intuit, Inc. |
| .SDL | Microsoft Corporation | File sviluppatore | Service Description Language File | Safari | Apple |
| .SED | Microsoft Corporation | File sviluppatore | IExpress Self Extraction Directive File | Microsoft IExpress Wizard | Microsoft Corporation |
| .SEM | Alpha Software | File sviluppatore | Alpha Five Set Data Dictionary Memo File | Alpha Anywhere - Alpha Software | Alpha Software |
| .SET | Xerox | File sviluppatore | Document Library Property Set File | Xerox Library Administration Tool | Fuji Xerox |
| .SETUP | Crytek | File sviluppatore | CryENGINE Character Setup File | Crytek CryENGINE SDK | Crytek |
| .SEX | Alpha Software | File sviluppatore | Alpha Five Set Data Dictionary Index File | Alpha Anywhere - Alpha Software | Alpha Software |
| .SF | Institut de Recherche et de Coordination Acoustique/Musique (IRCAM) | File sviluppatore | IRCAM Sound File | Awave Studio | FMJ-Software |
| .SH | Unknown Developer | File sviluppatore | Bash Shell Script | Notepad++ | Don Ho |
| .SHPROJ | Microsoft Corporation | File sviluppatore | Visual Studio Code Sharing App Project File | Microsoft Visual Studio | Microsoft Corporation |
| .SLL | ShopTalk Systems | File sviluppatore | Static Link Library | Shoptalk Systems Just BASIC | ShopTalk Systems |
| .SLN | Microsoft Corporation | File sviluppatore | Microsoft Visual Studio Solution File | VSoft Technologies FinalBuilder | VSoft Technologies |
| .SM | Open Source | File sviluppatore | StepMania Song File | StepMania | Open Source |
| .SMA | Don Ho | File sviluppatore | C/C++ Source Code File | MacroMates TextMate | MacroMates |
| .SMF | Oracle Corporation | File sviluppatore | StarMath Formula File | Apache OpenOffice | Apache Software Foundation |
| .SML | ESRI | File sviluppatore | ARC/INFO Simple Macro Language File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .SMW | Crestron Electronics | File sviluppatore | SIMPL Windows Source File | SIMPL Windows | Crestron Electronics |
| .SNIPPET | Microsoft Corporation | File sviluppatore | Visual Studio IntelliSense Code Snippet | Microsoft Visual Studio | Microsoft Corporation |
| .SO | GNU Project | File sviluppatore | Shared Library | GNU Compiler Collection (GCC) | GNU Project |
| .SPEC | Open Source | File sviluppatore | RPM Specification File | Notepad++ | Don Ho |
| .SPT | Interactive Data Visualization, Inc. | File sviluppatore | SpeedTree Tree Data File | SpeedTree Architect | Interactive Data Visualization, Inc. |
| .SPYX | Sage | File sviluppatore | Sage Compiled Source Code | Sage One | Sage |
| .SQC | SAP | File sviluppatore | SQL Common Code Data | SQL Anywhere | SAP |
| .SQLPROJ | Microsoft Corporation | File sviluppatore | Microsoft Visual Studio SQL Server Project | Microsoft Visual Studio | Microsoft Corporation |
| .SQML | Open Source | File sviluppatore | Standard Query Markup Language Document | SQML | Open Source |
| .SRA | Sybase, Inc | File sviluppatore | PowerBuilder Application | PowerBuilder | SAP |
| .SRC | Unknown Developer | File sviluppatore | Source Code File | Microsoft Notepad | Microsoft Corporation |
| .SRJ | Sybase, Inc | File sviluppatore | PowerBuilder Extension File | PowerBuilder | SAP |
| .SRQ | Microsoft Corporation | File sviluppatore | Microsoft Windows Server Unprocessed Request File | Microsoft Windows Server 2016 | Microsoft Corporation |
| .SRU | Sybase, Inc | File sviluppatore | PowerBuilder User Object | PowerBuilder | SAP |
| .SRZ | Data Access Worldwide | File sviluppatore | DataFlex Source Code | DataFlex | Data Access Worldwide |
| .SS | Open Source | File sviluppatore | SilverStripe Source Code File | SilverStripe | Open Source |
| .SSC | Microsoft Corporation | File sviluppatore | SourceSafe Status File | Microsoft Visual Studio | Microsoft Corporation |
| .SSI | Adobe Systems Incorporated | File sviluppatore | Adobe Dreamweaver Server Side Include File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .SSQ | Microsoft Corporation | File sviluppatore | ODBC Script File | Microsoft ODBC Data Source Administrator | Microsoft Corporation |
| .STS | DuoS DSEMU | File sviluppatore | DuoS DSEMU Saved State File | DuoS DSEMU | Unknown Developer |
| .SUBLIME-BUILD | Sublime HQ Pty Ltd | File sviluppatore | Sublime Text Build Data | Sublime Text | Sublime HQ Pty Ltd |
| .SUD | Aivosto Oy | File sviluppatore | Super Project Analyzer Data File | Super Project Analyzer | Aivosto Oy |
| .SUO | Microsoft Corporation | File sviluppatore | Visual Studio Solution User Options File | Microsoft Visual Studio | Microsoft Corporation |
| .SUP | Unknown Developer | File sviluppatore | Subtitle Bitmap File | IfoEdit | Open Source |
| .SUS | SAP | File sviluppatore | SAP Transactionware GM POS Xpress Suspended Data | SAP BusinessObjects Business Intelligence | SAP |
| .SVB | StatSoft, Inc. | File sviluppatore | Statistica Macro File | STATISTICA | StatSoft, Inc. |
| .SVH | IEEE Xplore | File sviluppatore | SystemVerilog Source Code Header File | Microsoft Notepad | Microsoft Corporation |
| .SVX | The Survex Project | File sviluppatore | Survex Cavern Data File | Microsoft Notepad | Microsoft Corporation |
| .SWC | Adobe Systems Incorporated | File sviluppatore | Flex Components Archive | Adobe Animate CC 2017 | Adobe Systems Incorporated |
| .SWD | Adobe Systems Incorporated | File sviluppatore | Flash Debug File | Adobe Flash Player | Adobe Systems Incorporated |
| .SXS | SAS Institute Inc. | File sviluppatore | SAS Stat Studio Module Source Code File | SAS | SAS Institute Inc. |
| .SYM | The Eclipse Foundation | File sviluppatore | Symbols File | Eclipse CDT | The Eclipse Foundation |
di 1 
