WhatFormat 'knows' the following applications. Though filename extensions are mentioned in the 'Used for' sections (just because this is shorter), the applications are associated with the headers, and not with the extensions.

-- CdPlayer --

-Used name: CdPlayer
-Search key: cdplayer.exe
-Available: W9x?
-Used for: cda

-- Imaging --

-Used name: Imaging
-Search key: kodakprv.exe or wangimg.exe
-Available: At least Windows 98, but also newer versions of Windows 95 and NT 4.0?
-Application homepage
-Used for: tif, awd, bmp, jpg, jpe, jpeg, pcx, gif, dcx

-- Media Player --

-Used name: MPlayer
-Search key: mplayer.exe
-Available: Any Windows?
-Application homepage
-Used for: mid, mpg, avi, wav, rmi, aif, au

-- Notepad --

-Used name: Notepad
-Search key: notepad.exe
-Available: Any Windows version
-Used for: Various text files (txt, asc etc.)

-- PaintBrush (if used on Windows 3.11 or below) --

-Used name: PaintBrush
-Search key: pbrush.exe
-Available: Windows 3.11 or below
-Used for: bmp, msp, pcx

-- Paint (if used on Windows 95 or higher) --

-Used name: Paint
-Search key: mspaint.exe
-Available: Windows 9x
-Used for: bmp, dib, rle

-- QuickView --

-Used name: QuickView
-Search key: quikview.exe
-Available: Windows 9x
-Application homepage
-Used for: Executables (exe, dll etc.), WP documents (wpd, wp5 etc.), Various text files (txt, asc etc.), Word (doc), wps, wri, Ms Excel 4.0 spreadsheets (xls), bmp, dib, rle, cur, db, dbf, Ami Professional document (sam, sty), wb1, wb2, wq1, wk1, wk3, wk4, rtf, mdb

-- Write (if used on Windows 3.11 or below) --

-Used name: Write
-Search key: write.exe
-Available: Windows 3.11 or below
-Used for: Various text files (txt, asc etc.), wri

-- WordPad (if used on Windows 95 or higher) --

-Used name: Wordpad
-Search key: wordpad.exe
-Available: Windows 9x
-Used for: Various text files (txt, asc etc.), rtf, wri, Word (doc)

-- ACDSee --

-Used name: ACDSee
-Search key: acdsee32.exe
-Application homepage
-Used for: bmp, dib, rle, gif, iff, lbm, jpg, pcd, pcx, png, psd, tga, tiff, wmf, SoftImage (pic), dcx

-- FmView --
-Used name: FmView
-Search key: fmvdde3.exe (A .dll needs to be copied as an .exe, see FmView's help for more info.
-Application homepage
-Used for: simple text files, wri, Ms Word documents, bmp, dib, rle, pcx, wmf, ico, dll, exe, arj, lzh, zip, (db, dbf, mdb - ODBC needed), cab, wps, sam, xls, wk1, wk3, wk4, WordPerfect documents, cdr, rtf, html, avi, wav, ttf, fon

-- GoldWave --

-Used name: GoldWave
-Search key: goldwave.exe
-Application homepage
-Used for: afc, aif, iff, au, dwd, mat, sds, smp, snd, raw, voc, vox

-- Graphic Workshop --

-Used name: Gws
-Search key: gws.exe
-Application homepage
-Used for: mac, img, pcx, gif, tif, wpg, pic, tga, cut, bmp, msp, lbm, rle, jpg, jpe, art, iff, ras, hrz, dib, ico, avi, cdb, cpt, fit, cdr, bga, png, mpg, mov, fli, flc, pcd, wmf, clp, uue, cam

-- IrfanView32 --

-Used name: IrfanView
-Search key: i_view32.exe
-Application homepage
-Used for: jpg, gif, bmp, dib, rle, tif, png, pcx, tga, pcd, ras, ico, avi, wav, mid, rmi, wmf, emf, ppm, pgm, pbm, iff, lbm, ani, cur, psd, clp, eps, mpg, exe, dll, cam, psp

-- Microsoft Internet Explorer --

-Used name: IExplorer
-Search key: iexplore.exe
-Available: Probably on your Windows 95/98 cdrom, if not, check the application homepage
-Application homepage
-Used for: gif, jpg, html, swf, rm, ram, ra

-- Netscape Navigator --

-Used name: NNavigator
-Search key: netscape.exe
-Application homepage
-Used for: gif, jpg, html, swf, rm, ram, ra

-- Paint Shop Pro --

-Used name: Psp
-Search key: psp.exe
-Application homepage
-Used for: bmp, dib, rle, cdr, cgm, clp, cmx, cut, drw, dxf, gem, gif, hgl, iff, lbm, img, jif, jpg, mac, msp, pbm, pcd, pct, pcx, pgm, pic, png, ppm, psd, ras, raw, tga, tif, wmf, wpg, fpx, psp, emf, dcx

-- PkZip --

-Used name: PkZip
-Search key: pkzipw.exe
-Application homepage
-Used for: zip, uue, gz, tgz

-- RealPlayer --

-Used name: RealPlayer
-Search key: realplay.exe
-Application homepage
-Used for: rm, ram, ra, swf

-- WinZip --

-Used name: WinZip
-Search key: winzip32.exe
-Application homepage
-Used for: arc, arj, lzh, zip, Ms Compress archives (??_, ??$), uue, gz, tgz, cab

-- Xnview --

-Used name: Xnview
-Search key: xnview.exe
-Application homepage
-Used for: jpg, tga, lbm, gif, SoftImage (pic), rgb, tif, Vista image (vst), ras, pct, bmp, png, pcx, ppm, pgm, pbm, psd, GEM Paint (img), Vivid (img), ico, cur, fit, pcd, mac, dcx