List Of All Extensions And Filetypes - J

This is an easy approach from me to give and describe each and every filetype and extension as much as possible.
here is the list for the information about various filetypes and extensions starting from alphabet J

Extension	Information
J	JPEG / JFIF Image
J	JAR Compressed File
J	Java Source Code (Sun)
J1	EDIT Compiler JEDEC Boundary File
J2A	Jazz Jackrabbit 2 Animation Library (Epic MegaGames Inc.)
J2B	Jazz Jackrabbit 2 Music File (Epic MegaGames, Inc.)
J2D	Jazz Jackrabbit Data File (Epic MegaGames, Inc.)
J2E	Jazz Jackrabbit 2 Episode File (Epic MegaGames, Inc.)
J2G	J2 Fax File
J2H	Jazz Jackrabbit 2 High Scores (Epic MegaGames, Inc.)
J2I	Jazz Jackrabbit 2 Internet Server Link (Epic MegaGames, Inc.)
J2K	JPEG-2000 JP2 File
J2L	Jaxx Creation Station Level File (Epic MegaGames Inc.)
J2M	Jazz Jackrabbit 2 Recorded Macro (Epic MegaGames, Inc.)
J2S	Jazz Jackrabbit 2 Language Data (Epic MegaGames, Inc.)
J2T	Jazz Jackrabbit 2 Tile Set (Epic MegaGames, Inc.)
J2V	Jazz Jackrabbit 2 Cinematic File (Epic MegaGames, Inc.)
J62	Ricoh Digital Camera File
J6I	Ricoh Digital Camera File (Ricoh Co., Ltd.)
J92	Javelin Configuration File (Minisoft Inc.)
JA	IBM Tools Updater File
JA	Trainz Railroad Simulator Game Content (Auran Games)
JACKET	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JACKSUM	Jacksum Fingerprint (Dipl.-Inf. (FH) Johann N. Löfflmann)
JAD	Java Application Descriptor File (Sun Microsystems, Inc.)
JAG	Jaguar Server File
JAIL	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAM	Image Microprose
JAM	JamTracker Music Module
JAM	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAM	Joaquim-Andrew-Mats Message Base Proposal
JAM	FTN Software Jam Messagebase
JAM	E-mail
JAM2	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAMMIX	Jammix Enhacer Music Transform File (Danilics Tibor)
JAN93	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAP	JAlbum Project File (Datadosen)
JAP	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAP	Fifa World Cup Game Data fe Art Legalscr File
JAPAN	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAR	Java Applet (Sun)
JAR	JARCS Compressed Archive (JPMdL Archival System)
JAR	Java Archive (Sun Microsystems, Inc.)
JAR	JAR Archive (ARJ Software, Inc.)
JARRE	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JAS	Paint Shop Pro Compressed Graphic (Corel Corporation)
JASC	JAS Compressed Graphic
JAU	Jauge
JAV	Java Source Code (Sun)
JAVA	Java Source Code (Sun)
JAW	IchiTaro Web Japanese Extended WordProcessor (Justsystem Corporation)
JB2	JBIG2 Bitmap Graphic
JBA	Jabaco Source Code Programming Language (Jabaco)
JBB	JobEditor32 Binary Job Data (Motoman Inc.)
JBC	BestCrypt Container (Jetico, Inc.)
JBC	Jam Byte-Codec File
JBD	SigmaScan Data File
JBF	Paint Shop Pro Browser Cache (Corel Corporation)
JBF	Backup Now Backed Up File (JetSoft Corporation)
JBG	JBIG File
JBI	JobEditor32 ASCII Job Data (Motoman Inc.)
JBIG	JBIG File
JBIG2	JBIG2 Bitmap Graphic
JBK	Jot + Notes Backup File for Older Version (King Stairs Software)
JBK	Juno Backup File
JBL	Doom Scene Add-in (Id Software, Inc.)
JBP	DJ Jukebox Project
JBR	Paint Shop Pro Brush (Corel Corporation)
JBS	DesignArt Vector Graphic (Océ N.V.)
JBX	Project Scheduler File
JC	FlashGet Intermediate Download (Beijing Zhitongwuxian Tech, Ltd.)
JC	Watcom Source File
JC!	FlashGet Incomplete Download (Beijing Zhitongwuxian Tech, Ltd.)
JCAMP	Misc
JCB	CB-JCBrooke Song/Module
JCC	Code Crusader Project Data (New Planet Software)
JCC	Japan Crossword Dmitry Torshin Format File (EliteWare)
JCD	FlashGet Download Database File (Beijing Zhitongwuxian Tech, Ltd.)
JCE	JWPce (Glenn Rosenthal)
JCF	JAWS for Windows Configuration File (Freedom Scientific)
JCK	Liquid Motion JACK Scene Description
JCL	Job Control Language IBM
JCM	Java Commerce Message Commerce Message (Wallet) (Sun)
JCP	Jesusonic Preset (Cockos Incorporated)
JCS	Latest Bruker WinSpecEdit v3.08 JCAMP
JCS	Flashget Script HTML Table
JCV	Baseball/Golf Analyzer (JC Video Systems)
JD	Jigsaw Terminal File
JDA	Winphone Fax Send Journal
JDB	Siren Jukebox
JDB	Winphone Fax Receive Journal
JDB	Norton AntiVirus Update File (Symantec Corporation)
JDBG	Project JEDI Embedded JCL Debug Information (Project JEDI)
JDE	Cariverona
JDF	Turok 2 Game File
JDF	JAWS for Windows Voice Synth File (Freedom Scientific)
JDF	Job Definition Format Job File
JDT	Capture Classic Filler (Accelio)
JDX	EDICT Index
JDX	JCAMP Chemical Spectroscopic Data Exchange Format (MDL Information Systems, Inc.)
JDX	J Database Exchange (JDX) O/R Mapping Specification (Software Tree, Inc.)
JDX	JSpell UNICODE Dictionary (Page Scholar Inc.)
JED	Xilinx Integrated Software Environment Device Configuration Information (Xilinx, Inc.)
JED	JEDEC Programming Specification
JEF	Janome NH10000 Sewing Machine Stitch File (Janome America, Inc.)
JEQ	Jet Audio Saved Equalizer Setting (JetAudio, Inc.)
JESD	JZEasyText Word Processor Save File (JamesZhu Inc.)
JET	Jetpack User-created Level Map
JET	Hybrid JetFax Fax
JFD	FormWare Job
JFD	JAWS for Windows (Freedom Scientific)
JFF	JAWS for Windows (Freedom Scientific)
JFF	JPEG Image
JFG	jEEPers User Specific Information
JFI	JPEG/JIFF Image
JFIF	JPEG/JIFF Image
JFM	Capture Classic (Accelio)
JFX	J2 Fax File
JG6	BigJig Jigsaw (Lena Pankratova)
JGCSCS	EditPad Pro Custom Coloring Scheme (JGsoft - Just Great Software)
JGD	Paint Shop Pro Gradient (Corel Corporation)
JGF	JAWS for Windows Configuration File (Freedom Scientific)
JGF	Jetcam Geometry File (JETCAM International, Ltd.)
JGL	QWS3270 PLUS Session Layout File (Jolly Giant Software Inc.)
JGP	QWS3270 PLUS Session Parameter File (Jolly Giant Software Inc.)
JGS	QWS3270 PLUS Script (Jolly Giant Software Inc.)
JGW	Map File
JHTM	Dynamo Server Page
JHTML	Dynamo Server Page
JIF	JPEG/JIFF Image
JIF	Jeff's Image Format Bitmap
JIG	Living Scenes Jigsaw Puzzles (Carolina Road Software L.L.C.)
JIG	Jigsaw Game (GameHouse, Inc., a division of RealNetworks, Inc.)
JIGDO	Jigsaw Download Download Instruction File (Richard Atterer)
JIM	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JINKS	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JIS	Japanese Industrial Standard Text File
JJ	JavaCC File
JJ	C64 Doodle Compressed File
JJC	Canvas Compressed Audio File
JJF	Jester Jugglor File
JKL	Jedi Knight
JKM	JAWS for Windows Configuration File (Freedom Scientific)
JKS	keytool Java Keystore (Sun Microsystems, Inc.)
JKS	Jedi Knight Backup
JL	Sawfish Lisp-based Script
JLA	VisualPro BMP Image
JLAB	JLab Program Source Code (Linova)
JLC	Sawfish Byte Compiled Lisp-based Script
JLF	JetLinks Bookmark Managment
JLP	JLIP Video Capture (Video Producer) Index Format Display (JVC)
JLS	JPEG-LS File
JLS	JAWS for Windows (Freedom Scientific)
JMA	Super Nintendo NSRT Compressed Game (Nintendo)
JMAN	Illum Source Irohaserver File
JMD	Paint Shop Pro Image Map Settings (Corel Corporation)
JMF	Java Multimedia File (Sun)
JMG	16 Bit Adaptive RLE Compressed Bitmap
JMH	JPEG File Interchange Format
JMK	Code Crusader Build Script (New Planet Software)
JMM	Digital Camera Video Clip (JVC)
JMP	SAS JMP Discovery Chart-to-Statistics File (SAS Institute Inc.)
JMS	SpamProx Blocking List (Dewqs' Tribes)
JMS	UltraForce Music Format
JMS	Voxtron TeleButler Graphical Voice Response Call Flow
JMX	JMeter File
JN1	Epic MegaGames Jill of the Jungle Data File
JNB	SigmaPlot Workbook File (SYSTAT Software Inc.)
JNC	Communication Log File
JNG	JPEG Network Graphic Bitmap
JNGL	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JNK	Junk
JNL	ISC BIND Journal File (Internet Systems Consortium)
JNL	Ingres Journal File (Computer Associates International, Inc.)
JNL	Journal Macro Data File (Chosen Software)
JNL	WINDEV Log File (PC SOFT)
JNLP	Java Web Start (Sun Microsystems, Inc.)
JNT	Windows XP Tablet PC Edition Journal (Microsoft Corporation)
JOB	Survey Pro Job (Tripod Data Systems)
JOB	QuestVision Vector Graphics File
JOB	AI Research
JOB	MicroSim PCBoard External ASCII Job File
JOB	Job File
JOB	File Invesigator Script Commands
JOB	BETA 44 Job File
JOB	Systems Management Server (SMS) Job File (Microsoft Corporation)
JOB	MetaCAM Nest Job (Metamation, Inc.)
JOB	Windows Task Scheduler Task Object (Microsoft Corporation)
JOBOPTIONS	Acrobat Job Options File (Adobe Systems Incorporated)
JOBS	VirtualDub Job Control File (Avery Lee)
JOC	Context4 DOS Word Processor File
JOCL	Java Object Configuration Language
JOD	MS.Jet.OLEDB.4.0 Related File
JOI	Xboard Join Conferences File
JOINED	HJSplit Default Joined File (Freebyte.com)
JOKE	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JONES	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JOR	Gupta SQLWindows Journal
JOR	SQL Server Journal File (Microsoft Corporation)
JOT	Jot + Notes Note Data File (King Stairs Software)
JOT	WinJottr Desktop Note
JOT	JDesignerPro File
JOU	VAX Edt Editor Journal File
JOURNAL	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JOY	Joystick Calibration File
JOY	Trackjoy GUS Tracker Module
JP2	Jeoparty II Presentation (Matthew Hagaman)
JP2	JPEG-2000 JP2 File
JP3	Electric Quilt File
JP4	Electric Quilt File
JP5	Electric Quilt File
JPA	JoomlaPack Joomla Installation Backup (fronzenFX)
JPC	Japan Picture Format
JPC	Jprobe Coverage Memory Snapshot (Quest Software Inc.)
JPC	JPEG-2000 Code Stream Bitmap
JPE	JPEG/JIFF Image
JPEG	JPEG/JIFF Image
JPEGENX	egis Encrypted JPEG File (HiTRUST Inc.)
JPF	Biz Plan Pro Business Plan Contents (JIAN Tools For Sales, Inc.)
JPF	Mass Center Main Mass Spectrometry Data (JEOL USA, Inc.)
JPG	CompactDRAW e-JPG Graphic (MediaChance)
JPG	JPEG/JIFF Image
JPGENX	egis Encrypted JPG File (HiTRUST Inc.)
JPG_T	JPG Image File
JPH	Jprobe Memory Debugger Memory Snapshot (Quest Software Inc.)
JPI	Jupiter Document (Elfin Sp. z o.o.)
JPL	Jprobe Settings File (Quest Software Inc.)
JPL	Siren Jukebox
JPM	LuraDocument.jpm Compressed PDF File (Algo Vision LuraTech GmbH)
JPN	Photomodeler Lite File
JPOW	JPowered Java Bar Charts
JPP	Jigsaw Puzzle Player Puzzle Definition (B&P Games B.V.)
JPP	Jprobe Profiler Memory Snapshot (Quest Software Inc.)
JPR	Javasockets File
JPR	Oracle JDeveloper Model JProject
JPS	Print Studio Graphic (Jolly, Inc.)
JPS	Jigsaw Puzzle Player Puzzle Completion Status (B&P Games B.V.)
JPS	Stereo Image
JPT	Jprobe Threadalyzer Memory Snapshot (Quest Software Inc.)
JPT	Print Studio Template (Jolly, Inc.)
JPX	JAlbum jalbum image info
JPX	JBuilder Project File (Borland Software Corporation)
JPX	JPEG-2000 JP2 File
JQX	Windows Help Related File (Microsoft Corporation)
JQZ	JQuiz Quiz File
JR	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JR2	FishSim Add-on (J.C.Spooner)
JRC	Jrchive Compressed Archive
JRF	winIDEA Workspace (Programming Project File) (iSYSTEM AG)
JRF	The Jumbot Bot Level Navigation File
JRL	Top Secret Crypto Gold Top Secret Journal File (TAN$TAAFL Software Company)
JRL	BioWare Aurora Engine Journal (BioWare Corp.)
JRP	Electric Quilt File
JRP	Pg4uw Job Report File (Elnec s.r.o.)
JRXML	JasperReports JRXML Report Definition (JasperSoft Corporation)
JS	JavaScript Source Code
JS	Mozilla (Netscape) Settings (Mozilla.org)
JS	JACOsub Script
JS	JetScript Output File
JSB	JavaScript Bean (JSB) File
JSB	JAWS for Windows Script Binary File (Freedom Scientific)
JSCRIPT	GoLive JavaScript (Adobe Systems Incorporated)
JSD	Join-Split File
JSD	eFAX Jet Suite Document (j2 Global Communications, Inc.)
JSD	Paint Shop Pro Image Slice Settings (Corel Corporation)
JSD	JAWS for Windows Script Documentation File (Freedom Scientific)
JSDB	JumpStart Database (Jumpstart-it.com)
JSE	JScript Encoded Script File
JSE	Fichier Encoded Javascript
JSF	Macromedia Fireworks Batch Script
JSF	Jahshaka Scene File (The Jahshaka Project)
JSFL	Flash Javascript (Adobe Systems Incorporated)
JSH	JAWS for Windows Script Header File (Freedom Scientific)
JSL	Visual J# Code (Microsoft Corporation)
JSL	Paint Shop Pro Shapes File (Corel Corporation)
JSM	JAWS for Windows Script Message File (Freedom Scientific)
JSM	Gray Design Associates Jigsaws Galore Jigsaw File
JSM	JugWin Jigsaw
JSM	Jig ShapeMap (Steamboat Software)
JSML	JSim Markup Language File (University of Washington)
JSN	Shield Now Shield File (JetSoft Corporation)
JSO	Various Programs JISO Compressed Disk Image File
JSON	Firefox Bookmark Backup (Mozilla)
JSON	JavaScript Object Notation
JSON	Google Gears Manifest File (Google)
JSP	Java Server Page (Sun)
JSP10	Java Server Page (Sun)
JSPA	WebWork Framework JSP Action
JSPF	JSP Page Fragment (Sun)
JSRC	Jabaco Source Code Programming Language (Jabaco)
JSS	JSheet
JSS	Gray Design Associates Jigsaws Galore Saved Game Jigsaw File
JSS	JugWin Jigsaw
JSS	JAWS for Windows Script Source File (Freedom Scientific)
JST	Jnes Saved Game State File (JaboSoft)
JST	Code Crusader Symbol Database (New Planet Software)
JSV	HyperRail 3D Coaster Design Construction File
JSV	Japanese Flash Card File
JSV	Java Structure Viewer
JSV	VXML JavaServer Page
JSW	WML JavaServer Page
JSX	After Effects Script File (Adobe Systems Incorporated)
JT	JT Fax
JTD	Ichitaro Document (Justsystem Corporation)
JTF	JPEG Tagged Interchange Format Image
JTF	Hayes JT Fax
JTIF	JPEG Tagged Interchange Format Image
JTK	Java ToolKit File (Sun)
JTL	JTool Data File (Behavioral Health Quality)
JTP	Windows XP Tablet PC Edition Journal (Microsoft Corporation)
JTP	JetForm File
JTR	Jelbert GeoTagger Location Database (Jelbert Consulting)
JUDI	JudoScript Source Code File (JudoScript.COM)
JUDO	JudoScript Source Code File (JudoScript.COM)
JUL	Inteliweb Program Registration and Validation (InVision Marketing, Inc. & Inteliweb.net)
JUL	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JUMP	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JUMP1	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JUN14	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JUP	Code Crusader User-Specific Project Preferences (New Planet Software)
JURL	JustUrls Button File (Eastern Digital Pty. Ltd.)
JUST	Unknown Apple II File (found on Golden Orchard Apple II CD Rom)
JUT	Jutvision Scene
JVC	Digital Camera File
JVS	Jpeg Video Sequencer Sequenced JPEG Images
JW	MS Wordpad, Works for windows v3.0 & 4.0
JW	Legacy Version 1.1
JW	Q & A Write for Windows 3.0
JW	Justwrite Text
JW	Jigsaw Terminal File
JWC	JewelCase Maker Saved File (NewTech Infosystems Inc.)
JWC	Jw_cad Data (Jiro Shimizu & Yoshifumi Tanaka)
JWL	Easy CD Creator's CD Label (Sonic Solutions)
JWL	Jewel Case Creator CD Disc Case
JWL	Justwrite Text File Library
JWP	JWP Document
JWP	Easy CD Creator Label File (Sonic Solutions)
JWR	LegaSuite GUI J Walk Runtime File (Seagull Software Systems, Inc.)
JWS	WebLogic Workshop Java Web Services (BEA Systems, Inc.)
JXDM	Multi-Channel Server (MCS) Markup Editor Java Server Page with XDIME Markup/Java Code (Volantis Systems Ltd.)
JXT	Daqarta Extended Audio Data (Interstellar Research)
JXX	C++ Header File
JZ	JamesZhu Internet Browser Database File (JamesZhu, Inc.)
JZZ	Jazz Spreadsheet