Linux alternatives

Windows : 3D Home Architect
Sweet Home 3D (http://sweethome3d.sourceforge.net/index.html)

Windows: 3D Studio Max
Art of Illusion (http://www.artofillusion.org/)
Blender (http://www.blender.org/)
K-3D (http://www.k-3d.org/)
Wings 3D (http://www.wings3d.com/)

Windows: ACDSee
Eye of GNOME (http://www.gnome.org/projects/eog/)
Geeqie (http://geeqie.sourceforge.net/)
GQview (http://gqview.sourceforge.net/)
Gwenview (http://gwenview.sourceforge.net/)
KuickShow (http://kuickshow.sourceforge.net/)
ShowImg (http://www.jalix.org/projects/showimg/)

Windows : Adobe Acrobat Reader
ePDFView (http://trac.emma-soft.com/epdfview/)
Evince (http://www.gnome.org/projects/evince/)
KPDF (http://kpdf.kde.org/)
okular (http://okular.kde.org/)
Xpdf (http://www.foolabs.com/xpdf/)

Windows : Adobe Audition
Audacity (http://audacity.sourceforge.net/)

Windows : Adobe Illustrator
Inkscape (http://www.inkscape.org/)
sK1 Project (http://ww.sk1project.org/)
Skencil (http://www.skencil.org/)
Xara Xtreme for Linux (http://www.xaraxtreme.org/)

Windows : Adobe Lightroom
Darktable (http://darktable.sourceforge.net/)

Windows : Adobe PageMaker
Scribus (http://www.scribus.net/)

Windows : Adobe Photoshop
CinePaint (http://www.cinepaint.org/)
GIMP (http://www.gimp.org/)

Windows : Ant Movie Catalog
Moviefly (https://savannah.nongnu.org/projects/lmc/)

Windows : AOL Instant Messenger (AIM)
Instantbird (http://instantbird.com/)
Kopete (http://kopete.kde.org/)
Pidgin (http://pidgin.im)
PSI (http://psi-im.org/)

Windows : APC PowerChute
Apcupsd (http://www.apcupsd.com/)
Network UPS Tools (http://www.networkupstools.org/)
PowerD (http://power.sourceforge.net/)

Windows : Collectorz
Alexandria (http://alexandria.rubyforge.org/)
aviManager (http://avimanager.sourceforge.net/)
GCstar (http://www.gcstar.org/)
Griffith (http://griffith.cc/)
Katalog (http://salvaste.altervista.org/)
Tellico (http://tellico-project.org/)
vMovieDB (http://vmoviedb.sourceforge.net/)

Windows : DAMN NFO Viewer
NFO Viewer (http://home.gna.org/nfoview/)

Windows: DVDShrink
AcidRip (http://untrepid.com/acidrip/)
dvd::rip (http://www.exit1.org/dvdrip/)
k9copy (http://k9copy.sourceforge.net/)
OGMRip (http://ogmrip.sourceforge.net/)
qVamps (http://vamps.sourceforge.net/)
Thoggen (http://thoggen.net/)
xdvdshrink (http://dvdshrink.sourceforge.net/)

Windows: Ecco Pro
BasKet (http://basket.kde.org/)
Chandler (http://chandlerproject.org/)
QuickFox Notes (https://addons.mozilla.org/en-US/firefox/addon/13572/)
Tomboy (http://live.gnome.org/Tomboy/)
Zim (http://zim-wiki.org/)

Windows: Everest
HardInfo (http://hardinfo.berlios.de/web/HomePage)

Windows: FL Studio
Ardour (http://www.ardour.org)
Jokosher (http://www.jokosher.org/)
LMMS (http://lmms.sourceforge.net/)

Windows: Fontographer
FontForge (http://fontforge.sourceforge.net/)

Windows: foobar2000
Amarok (http://amarok.kde.org/)
Aqualung (http://aqualung.factorial.hu/misc.html)
aTunes (http://www.atunes.org/)
Banshee (http://banshee-project.org/Main_Page)
deadbeef (http://deadbeef.sourceforge.net/)
Decibel Auto Player (http://decibel.silent-blade.org/)
Exaile (http://www.exaile.org/)
gmusicbrowser (http://gmusicbrowser.org/)
gtkpod (http://www.gtkpod.org/)
Listen (http://listengnome.free.fr/)
minitunes (http://flavio.tordini.org/minitunes)
Musique (http://flavio.tordini.org/musique)
Quod Libet (http://code.google.com/p/quodlibet/)
Rhythmbox (http://www.gnome.org/projects/rhythmbox/)

Windows: Forte Agent
Pan (http://pan.rebelbase.com/)

Windows: Fraps
recordMyDesktop (http://recordmydesktop.sourceforge.net/)
Yukon (https://github.com/wereHamster/yukon/)

Windows: FreeRIP
Grip (http://nostatic.org/grip/)
KAudioCreator (http://www.icefox.net/programs/?program=KAudioCreator)
ripperX (http://ripperx.sourceforge.net/)
Rubyripper (http://wiki.hydrogenaudio.org/index.php?title=Rubyripper)
Sound Juicer (http://www.burtonini.com/blog/computers/sound-juicer)

Windows: FruityLoops
Hydrogen (http://www.hydrogen-music.org/)

Windows: Google Desktop Search
Beagle (http://beagle-project.org/)
Google Desktop (http://desktop.google.com/linux/index.html)

Windows: Google Earth
Earth 3D (http://www.earth3d.org/)
Marble (http://edu.kde.org/marble/)

Windows: Guitar Pro
DGuitar (http://dguitar.sourceforge.net/)
kguitar (http://sourceforge.net/projects/kguitar/)
TuxGuitar (http://www.tuxguitar.com.ar/home.html)

Windows: iView MediaPro
digiKam (http://www.digikam.org/)
F-Spot (http://f-spot.org/Main_Page)
flPhoto (http://www.easysw.com/~mike/flphoto/)
gThumb (http://live.gnome.org/gthumb/)
jBrout (http://jbrout.manatlan.com/)
KPhotoAlbum (http://www.kphotoalbum.org/)
Shotwell (http://www.yorba.org/shotwell/)

Windows: Legacy Family Tree
GRAMPS (http://gramps-project.org/)

Windows: LimeWire
FrostWire (http://www.frostwire.com/)

Windows: Meal Master
Gourmet Recipe Manager (http://grecipe-manager.sourceforge.net/)
krecipe (http://krecipes.sourceforge.net/)

Windows: Microsoft Access
GNOME-DB (http://www.gnome-db.org/)
knoda (http://knoda.sourceforge.net/)
LibreOffice Base (http://www.libreoffice.org/)

Windows: Microsoft Excel
Gnumeric (http://www.gnome.org/projects/gnumeric/)
LibreOffice Calc (http://www.libreoffice.org/)
Open Calc (http://www.openoffice.org/product/calc.html)

Windows: Microsoft Frontpage
Aptana (http://aptana.com/)
Bluefish (http://bluefish.openoffice.nl/index.html)
BlueGriffon (http://bluegriffon.org/)
Geany (http://geany.uvena.de)
KompoZer (http://www.kompozer.net/)
Nvu (http://www.nvu.com/)
Quanta Plus (http://quanta.kdewebdev.org/)
Screem (http://www.screem.org/)

Windows: Microsoft HyperTerminal
GtkTerm (http://freshmeat.net/projects/gtkterm/)
minicom (http://alioth.debian.org/projects/minicom/)

Windows: Microsoft Internet Explorer ou Edge
Epiphany (http://www.gnome.org/projects/epiphany/)
Firefox (http://www.mozilla.com/firefox/)
Konqueror (http://www.konqueror.org/)
Opera (http://www.opera.com/download/)

Windows: Microsoft Office
GNOME Office (http://www.gnome.org/gnome-office/)
LibreOffice (http://www.libreoffice.org/)
OpenOffice (http://www.openoffice.org/)

Windows: Microsoft Outlook
Evolution (http://www.gnome.org/projects/evolution/)
Thunderbird (http://www.mozilla.com/thunderbird/)

Windows: Microsoft Powerpoint
EASE Presentation Editor (http://www.ease-project.org/index.html)
LibreOffice Impress (http://www.libreoffice.org/)
Open Office Impress (http://www.openoffice.org/product/impress.html)

Windows: Microsoft Project
GanttProject (http://ganttproject.sourceforge.net/)
OpenProj (http://openproj.org/openproj)
Planner (http://live.gnome.org/Planner)
TaskJuggler (http://www.taskjuggler.org/)

Windows: Microsoft Visio
Dia (http://www.gnome.org/projects/dia/)
yEd (http://www.yworks.com/en/products_yed_about.html)

Windows: Microsoft Windows Media Center
Boxee (http://www.boxee.tv/)
Freevo (http://freevo.sourceforge.net/)
LinuxMCE (http://www.linuxmce.com/)
Moovida (http://www.moovida.com)
MythTV (http://www.mythtv.org)
XBMC Media Center (http://xbmc.org/)

Windows: Microsoft Word
AbiWord (http://www.abisource.com/)
LibreOffice Writer (http://www.libreoffice.org/)
Open Office Writer (http://www.openoffice.org/product/writer.html)

Windows: mIRC
BitchX (http://www.bitchx.org/)
ChatZilla! (http://chatzilla.hacksrus.com/)
irssi (http://www.irssi.org/)
Konversation (http://konversation.kde.org/)
KVIrc (http://www.kvirc.net/)
Pidgin (http://pidgin.im)
Xchat (http://www.xchat.org/)

Windows: Mp3tag
Audio Tag Tool (http://pwp.netcabo.pt/paol/tagtool/)
Cowbell (http://more-cowbell.org/)
EasyTAG (http://easytag.sourceforge.net/)
Kid3 (http://kid3.sourceforge.net/)
Pinkytagger (http://pinkytagger.sourceforge.net/)

Windows: MS Paint
KolourPaint (http://kolourpaint.sourceforge.net/)
Pencil (http://www.pencil-animation.org/)
Pinta (http://pinta-project.com/)
TuxPaint (http://tuxpaint.org/)

Windows: MSN messenger
aMSN (http://amsn-project.net/)
Kopete (http://kopete.kde.org/)
Mercury Messenger (http://www.mercury.to/)
Pidgin (http://pidgin.im)

Windows: Mudbox
SharpConstruct (http://sourceforge.net/projects/sharp3d/)

Windows: Nero Burning Rom
Brasero (http://perso.orange.fr/bonfire/index.htm)
GnomeBaker (http://gnomebaker.sourceforge.net/)
Graveman! (http://graveman.tuxfamily.org/)
K3b (http://www.k3b.org/)
X-CD-Roast (http://www.xcdroast.org/)

Windows: NetMeeting
Ekiga (http://www.gnomemeeting.org/)

Windows: NetStumbler
Kismet (http://www.kismetwireless.net/)
SWScanner (http://www.swscanner.org/)

Windows: NewzCrawler
Akregator (http://akregator.kde.org/)
BasKet (http://basket.kde.org/)
Blam (http://www.cmartin.tk/blam.html)
Liferea (http://liferea.sourceforge.net/)
RSSOwl (http://www.rssowl.org/)
Straw (http://www.gnome.org/projects/straw/)

Windows: Notepad
gedit (http://www.gnome.org/projects/gedit/)
jEdit (http://www.jedit.org/)
Kate (http://kate-editor.org/)
leafpad (http://tarot.freeshell.org/leafpad/)
NEdit (http://www.nedit.org/)
Scribes (http://scribes.sourceforge.net/)
tpad (http://tclpad.sourceforge.net/)

Windows: OrangeCD Catalog
GWhere (http://www.gwhere.org)

Windows: Origin
SciGraphica (http://scigraphica.sourceforge.net/)

Windows: Partition Magic
GParted (http://gparted.sourceforge.net/)
Palimpsest (http://library.gnome.org/users/palimpsest/)
Partimage (http://www.partimage.org/Main_Page)
QtParted (http://qtparted.sourceforge.net)

Windows: PhotoME
FotoTagger (http://sourceforge.net/projects/fototagger/)

Windows: Quicken
Gnofin (http://gnofin.sourceforge.net/)
GNUcash (http://www.gnucash.org/)
Grisbi (http://www.grisbi.org/)
HomeBank (http://homebank.free.fr/)
KMyMoney (http://kmymoney2.sourceforge.net/)
Skrooge (http://skrooge.org/)

Windows:Sibelius
Denemo (http://denemo.sourceforge.net/index.html)
Lilypond (http://www.lilypond.org)
MuseScore (http://musescore.org/)
NoteEdit (http://noteedit.berlios.de/)
Rosegarden (http://www.rosegardenmusic.com/)

Windows: SoulSeek
Nicotine (http://nicotine.thegraveyard.org/)
Nicotine-Plus (http://nicotine-plus.sourceforge.net/)

Windows: SoundForge
ReZound (http://rezound.sourceforge.net/)

Windows: Total Commander
GNOME Commander (http://www.nongnu.org/gcmd/)
Krusader (http://krusader.sourceforge.net/)
Midnight Commander (http://www.ibiblio.org/mc/)
Tux Commander (http://tuxcmd.sourceforge.net/)
xfe (http://roland65.free.fr/xfe/)

Windows: Traktor DJ
Mixxx (http://mixxx.sourceforge.net/)
terminatorX (http://www.terminatorx.org/)

Windows: TweetDeck
Choqok (http://choqok.gnufolks.org/)
Gwibber (http://gwibber.com/)
Hotot (http://www.hotot.org/features/)
Pino (http://pino-app.appspot.com/)

Windows: uTorrent
Deluge (http://deluge-torrent.org)
qBittorrent (http://qbittorrent.sourceforge.net/)
Transmission (http://www.transmissionbt.com/)

Windows: Videora
thin liquid film (http://thinliquidfilm.org/)

Windows: Winamp
Amarok (http://amarok.kde.org/)
Audacious (http://audacious-media-player.org/Main_Page)
deadbeef (http://deadbeef.sourceforge.net/)
Musique (http://flavio.tordini.org/musique)
Qmmp (http://qmmp.ylsoftware.com/)
XMMS (http://www.xmms.org/)

Windows: Windows Media Player
KPlayer (http://kplayer.sourceforge.net/)
mplayer (http://www.mplayerhq.hu/design7/news.html)
VLC Player (http://www.videolan.org/vlc/)
xine (http://xinehq.de/)

Windows: Windows Movie Maker
cinefx (http://www.cinefx.org/)
Cinelerra (http://cvs.cinelerra.org/)
Kdenlive (http://kdenlive.sourceforge.net/)
Kino (http://www.kinodv.org/)
LiVES (http://lives.sourceforge.net/)
Lombard (http://yorba.org/lombard/)
Open Movie Editor (http://www.openmovieeditor.org/)
OpenShot (http://www.openshotvideo.com/)
PiTiVi (http://www.pitivi.org/wiki/Main_Page)
VideoLAN Movie Creator (http://trac.videolan.org/vlmc/)

Windows: WinIso
KIso (http://kiso.sourceforge.net/)

Windows: WinMerge
KDiff3 (http://kdiff3.sourceforge.net/)
Kile (http://kile.sourceforge.net/)
Meld (http://meld.sourceforge.net/)
xxdiff (http://furius.ca/xxdiff/)

Windows: WinTV
KWinTV (http://www.kwintv.org/)
tvtime (http://tvtime.sourceforge.net/)
xawtv (http://linux.bytesex.org/xawtv/)
XdTV (http://xawdecode.sourceforge.net/)
Zapping (http://zapping.sourceforge.net/Zapping/index.html)

Windows: WS_FTP
FireFTP (http://fireftp.mozdev.org/)
gFTP (http://gftp.seul.org/)

Windows: ZoneAlarm
Firestarter (http://www.fs-security.com/)
Guarddog (http://www.simonzone.com/software/guarddog/)

Windows: Zscreen
Shutter (http://shutter-project.org/)