This page provides a handy guide to all the file extensions you can find on this site, as well as what you need to open or run them. Please note that it is not meant to be an exhaustive technical support page -- please read our comprehensive FAQ for general help, and visit the HOTU Tech Help page for game-specific help.

1) Compressed file formats

	Extension	What is it?	What do I need to open it?
	*.001, *.002 etc.	ARJ compressed files	WinRAR (use it on *.001 file; it will auto-extract the rest)
	*.ACE, *.C01 etc.	ACE compressed files	WinACE
	*.ARJ, *.A01 etc.	ARJ compressed files	WinRAR
	*.BZ2, *.TAR.BZ2	bzip2 compressed file	PowerArchiver
	*.RAR, *.R00 etc.	RAR compressed file	WinRAR
	*.ZIP	ZIP compressed file	WinZIP or WinRAR

2) Game file formats

	Extension	What is it?	What do I need to run it?
	*.ACD	ALAN game file	ALAN interpreter (see "Runtime only" section)
	*.BIN (small size)	Odyssey² game ROM	O2EM emulator
	*.BIN (large size)	SEGA Genesis/SEGA CD/Sony Playstation game file	GENS or ePSXe emulator
	*.BLB	Glulx game	Glulx interpreters
	*.C64, *.D64	Commodore 64 game ROM	CCS64 emulator (among others)
	*.DCR	Shockwave game	Shockwave player (if you already have the plug-in, just open the DCR file with your browser)
	*.DO	Apple II game ROM	AppleWin (Apple II emulator)
	*.DSK	Apple II or Macintosh game ROM	AppleWin (Apple II emulator) or Basilisk II (Mac emulator)
	*.FIG	Super Nintendo game file	SNES emulator - we recommend ZSNES
	*.GAM	TADS game file	Windows TADS 2+3 Player Kit Installer
	*.GG	SEGA Game Gear game file	MEKA emulator
	*.HEX	HUGO game file	HUGO interpreter
	*.HQX	Macintosh compressed file	A real Mac ;) or Basilisk II emulator
	*.IMG	Self-booter disk image	Flopper program
	*.ISO (non-PC title)	SEGA CD/Sony Playstation game file	GENS or ePSXe emulator
	*.ISO (PC title)	Exact copy ("ISO") of a PC CD-ROM disc	Daemon Tools - allows mounting *.ISO on a virtual CD-ROM drive
	*.JAR	Java Runtime file	Java Runtime Library
	*.MSA	Atari ST disk image	Steem Engine emulator
	*.MSI	Windows Installer database	Windows Installer update (for Win 95/98 users only)
	*.NES	Nintendo game file	NES emulator - we recommend NESticle
	*.NIB	Apple II game ROM	AppleWin (Apple II emulator)
	*.NRG	Exact copy ("ISO") of a PC CD-ROM disc	Daemon Tools - allows mounting *.NRG on a virtual CD-ROM drive
	*.PRG	Atari ST game ROM	Steem Engine emulator
	*.SFC	Super Famicom (SNES outside Asia) game file	SNES emulator - we recommend ZSNES
	*.SIT	Macintosh StuffIt file	A real Mac ;) or Basilisk II emulator
	*.SMC	Super Nintendo game file	SNES emulator - we recommend ZSNES
	*.SMD	SEGA 32X game file	GENS emulator
	*.SWF	Flash game	Shockwave Flash (if you already have the plug-in, just open the SWF file with your browser)
	*.ST	Atari ST game ROM	Steem Engine emulator
	*.T3	TADS 3 game file	Windows TADS 2+3 Player Kit Installer
	*.TAF	ADRIFT game file	ADRIFT Runner
	*.ULX	Glulx game	Glulx interpreters
	*.Z5, *.Z6, *.Z8	Inform game file	Windows Frotz 2002

3) Music file formats

	Extension	What is it?	What do I need to listen to it?
	*.D00, *.HSC, *.RAW, *.SA2	AdLib format file	AdPlug, a plug-in module for WinAmp
	*.MID, *.MIDI	MIDI file	Windows media player (pre-installed with Windows)
	*.MOD, *.ITZ, *.S3Z	Amiga music file	ModPlug (to listen directly) or DeliPlayer
	*.OGG	Ogg Vorbis music	Ogg player - dbPowerAMP is recommended
	*.SID	Commodore 64 music file	SidPlay for Windows or SidPlay for Mac
	*.ZIP	Compressed music file for DeliPlayer	DeliPlayer (no need to use WinZIP)