Open Source Software
      "Never trust salespeople who don't
        use their own products."
      - Preface, The Practice of System and
        Network Administration by Thomas A. Limoncelli & Christine Hogan
      
      Below is software that I use or have used before. I believe all of
      these projects to be usable replacements of their commercial
      counterparts (if a
      commercial equal exists). Most of these apps I have used for quite a
      while before adding them to this list. I consider them to be (or near)
      stable and
      of good quality.
      
      I currently am trying to make donations to some of
      my favorite projects to show my appreciation for the developer's hard
      work. I am
      more partial to projects that work on multiple platforms or are
      platform independent, since I work on multiple platforms and it's nice
      to
      use the same apps on each.
      
      New York Times Firefox Ad - PDF
      Closeup of my name in the ad :) - here
      Wikimedia Foundation featured comment (yess) - here
      X-mas card from Wikimedia Foundation - here
      Example of me using Dia - here
      
      Thus far I have donated to:
      Apache Software Foundation - 1 donation
      Audacity - 1 donation 
      Azureus - 1 donation
      BitTorrent - 1 donation
      Calibre - 1 donation 
      CDex - 1 donation
      ClamWin Antivirus - 1 donation
      Comix - 1 donation
      CyanogenMod - 1 donation
      Dev-C++ - 1 donation
      DOSBox - 3 donations
      FileZilla - 2 donations
FixParts - 1 donation
      Free Software Foundation - 1 donation
      GIMP - 2 donations
      GNOME - 5.5 donations
      HardInfo - 1 donation
      HSQLDB - 1 donation
      Hydrogen - 1 donation
      Internet Book List - 1 donation
      KDE - 3 donations
      Memtest86 - 1 donation
      Mozilla/Spread Firefox - 4 donations
      Notepad++ - 1 donation
      OpenBSD/OpenSSH, etc - 3 donations
      OpenOffice - 4 donations
      OpenShot - 2.5 donations
      SETI Spy - 1 donation
      SourceForge - 1 donation
      TightVNC - 1 donation
      Tomato Firmware - 1 donation
      VideoLAN - 1 donation
      VisualBoyAdvance - 1 donation
      Wikimedia Foundation (Wikipedia) - 7.5 donations (1 in 2014)
      Xiph.Org - 1 donation
      Zim - 1 donation
      ZSNES - 1 donation
      
      ^(1 donation = $10)^
      External link to Yahoo! Finance Currency Conversion - finance.yahoo.com/m3?u
      
      
      
        Instant Messaging/Chat
      Linux/Win32
      Gaim (now named Pidgin)
      Gaim-Encryption (now named Pidgin-Encryption)
      Pidgin/Finch - www.pidgin.im
      Pidgin-Encryption - pidgin-encrypt.sf.net
    
Linux Only
      Irssi - www.irssi.org
      
      Win32 Only
      HydraIRC - www.hydrairc.com
      
      
        Multimedia
      
        Linux/Win32
      Audacity - audacity.sf.net
      Avidemux - fixounet.free.fr/avidemux
      Cdrtools (Cdrecord) - cdrecord.berlios.de/old/private/cdrecord.html
      EasyTAG - easytag.sf.net
      GCstar - www.gcstar.org
      gPodder - www.gpodder.org
HandBrake - www.handbrake.fr
      VLC Media Player - www.videolan.org/vlc
      Linux MultiMedia Studio (LMMS) - lmms.sf.net
      Hydrogen - www.hydrogen-music.org
      Xvid - www.xvid.org
      Nosefart - nosefart.sf.net
      Sidplay2 - sidplay2.sf.net
      MikMod - mikmod.raphnet.net
      MilkyTracker - www.milkytracker.net
      Miro - www.getmiro.com
      Mixxx - mixxx.sf.net
      SoX - sox.sf.net
      
      
        Linux Only
      AcetoneISO - www.acetoneteam.org
      Audacious - audacious-media-player.org
      Banshee - www.banshee-project.org
      Brasero - projects.gnome.org/brasero
      Cheese - projects.gnome.org/cheese
      Festival - www.cstr.ed.ac.uk/projects/festival
      F-Spot - www.f-spot.org
      gtkpod (Banshee provides this program's functionality)
      guvcview - guvcview.berlios.de
      K3b - k3b.plainblack.com
      OpenShot - www.openshotvideo.com
      Qmmp - qmmp.ylsoftware.com/index_en.php
      rubyripper - code.google.com/p/rubyripper
      SoundConverter - soundconverter.berlios.de
      thoggen - www.thoggen.net
      X MultiMedia System (XMMS) (discontinued) 
      xvidcap - xvidcap.sf.net
      
      
        Win32 Only
      CDex - cdexos.sf.net
Greenshot - www.getgreenshot.org
      VirtualDub - www.virtualdub.org
      InfraRecorder - infrarecorder.sf.net
      CamStudio - www.camstudio.org
      MediaCoder (no longer open source)
Nightingale - www.getnightingale.com
      OpenPandora - openpandora.googlepages.com
      WinCDEmu - wincdemu.sysprogs.org
      Songbird (replaced by Nightingale)
      
      
        Office
      
        Linux/Win32
      AbiWord - www.abisource.com
      Aspell - aspell.sf.net
      Calcoo - calcoo.sf.net
      Calibre - www.calibre-ebook.com
      Dia - www.gnome.org/projects/dia
      DocSearcher - docsearcher.henschelsoft.de
      FreeMind - freemind.sf.net
      GPL Ghostscript - www.cs.wisc.edu/~ghost
      LibreOffice - www.libreoffice.org
      MSGViewer - www.freecode.com/projects/msgviewer
OpenOffice
      (succeeded by LibreOffice)
      RSSOwl - www.rssowl.org
      Truth Table Solver - truthtablesolve.sf.net
      wikidPad - wikidpad.sf.net
      XMind - www.xmind.net
      Zim - www.zim-wiki.org
      
      
        Linux Only
      Gnumeric - www.gnome.org/projects/gnumeric
      GnuCash - www.gnucash.org
      KOffice - www.koffice.org
      KchmViewer - www.kchmviewer.net
      Calctool (Gcalctool) - calctool.sf.net
      KPDF (replaced by Okular)
      GtkSpell - gtkspell.sf.net
      
      
        Win32 Only
      PDFCreator - sourceforge.net/projects/pdfcreator
      GraphCalc - gcalc.sf.net
      Sumatra PDF - blog.kowalczyk.info/software/sumatrapdf/index.html
      
      
        Boot disks/Boot utilities
      
        N/A
      BackTrack - www.backtrack-linux.org
      Memtest86 - www.memtest86.com
      Memtest86+ - www.memtest.org
      Darik's Boot and Nuke - dban.sf.net
      Knoppix - www.knoppix.org 
      Parted Magic - www.partedmagic.com
      
      
        Web applications
      
        N/A
      Alfresco - www.alfresco.com
      BBClone - www.bbclone.de
      Coppermine Photo Gallery - www.coppermine-gallery.net
      Drupal - www.drupal.org
      Joomla! - www.joomla.org
jsFiddle - www.jsfiddle.net (not sure if open source, but very useful)
MathJax - www.mathjax.org
      Matt's Whois - www.mattsscripts.co.uk/mwhois.htm
      MediaWiki - www.mediawiki.org
      My Calendar - www.fuzzymonkey.net/software/calendar
      PhpBB - www.phpbb.com
      phpDVD - ugo.scarlata.it/?pid=phpdvd
      phpMyInventory - phpmyinventory.sf.net
      PHPSysInfo - phpsysinfo.sf.net
quizzy - quizzy.sf.net
      Webmin - www.webmin.com
      WordPress - www.wordpress.org
      SSHTools - www.sf.net/projects/sshtools
      
      File Sharing/File Transfer 
      
        Linux/Win32
      BitTorrent (no longer open source)
      Azureus/Vuze (still open source, but commercialized & bloated)
      FileZilla - filezilla.sf.net
      JDownloader - www.jdownloader.org
      
      
        Linux Only
      gFTP - gftp.seul.org
      Monsoon (Transmission is more mature)
      Transmission - www.transmissionbt.com
      rTorrent - libtorrent.rakshasa.no
      
      
        Win32 Only
      WinSCP - www.winscp.net
    
File/System
        Utilities
      Linux/Win32
      B5I2ISO - developer.berlios.de/projects/b5i2iso
FixParts - www.rodsbooks.com/fixparts
      KDiff3 - kdiff3.sf.net
      mdf2iso - mdf2iso.berlios.de
      Nrg2Iso - gregory.kokanosky.free.fr/v4/linux/nrg2iso.en.html
      
      
        Linux Only
      alien - www.kitenet.net/~joey/code/alien
      Beagle - beagle-project.org
      convmv - www.j3e.de/linux/convmv
      Filelight - www.methylblue.com/filelight
      FUSE - fuse.sf.net
      GNOME Commander - www.nongnu.org/gcmd
      GParted - gparted.sf.net
      HardInfo - hardinfo.berlios.de
      htop - htop.sf.net
      inxi - code.google.com/p/inxi
      KDirStat - kdirstat.sf.net
      Krusader - krusader.sf.net
      Midnight Commander - www.ibiblio.org/mc
      Parted - www.gnu.org/software/parted
      ps3 - user.tninet.se/~uhu537u/ps3.html
      ncdu - dev.yorhel.nl/ncdu
      
      
        Win32 Only
      WinDirStat - windirstat.sf.net
      7-Zip
      - www.7-zip.org
      WinMerge - www.winmerge.org
      
      
        Emulation
      
        Linux/Win32
      Atari800 - atari800.sf.net
      Basilisk II - basilisk.cebix.net
      Caprice32 - www.caprice32.cybercube.com
      ColEm - fms.komkon.org/ColEm
      DeSmuME - www.desmume.org
      Dolphin - www.dolphin-emu.com
      DOSBox - dosbox.sf.net
      Dynagen - www.dynagen.org
      Dynamips - www.ipflow.utc.fr/index.php/Cisco_7200_Simulator
      FCE Ultra (succeeded by FCEUX)
      FCEUX - www.fceux.com
FS-UAE - www.fs-uae.net
      Fuse - fuse-emulator.sf.net
      Gens (succeeded by Gens/GS)
      Gens/GS - info.sonicretro.org/Gens/GS
      GNS3 - www.gns3.net
      Hatari - hatari.berlios.de
      Hu-Go! - www.zeograd.com
      JPCSP - www.jpcsp.org
      MEKA - www.smspower.org/meka
      Mupen64Plus - code.google.com/p/mupen64plus
      openMSX - openmsx.sf.net
      PCSX2 - www.pcsx2.net
      PCSX-Reloaded - pcsxr.codeplex.com
      Raine - rainemu.swishparty.co.uk
      Reality Boy - www.goliathindustries.com/vb
      ScummVM - www.scummvm.org
      
      Snes9x - www.snes9x.com
      Stella - stella.sf.net
      VICE - www.viceteam.org
      VirtualBox - www.virtualbox.org
      ZSNES - www.zsnes.com
VBA-M - www.vba-m.com
      Virtual Jaguar - icculus.org/virtualjaguar
      VisualBoyAdvance (succeeded by VBA-M)
      Yabause - www.yabause.org
      
      
        Linux Only
      Wine - www.winehq.com
      DOSEMU - www.dosemu.org
      FreeDOS - www.freedos.org
      GFCE Ultra (merged into FCEUX)
      Open VM Tools - open-vm-tools.sf.net
      SDLMAME - rbelmont.mameworld.info/?page_id=163
      Wiithon - https://launchpad.net/wiithon
      
      
        Win32 Only
      WinUAE - www.winuae.net
      Multiple Arcade Machine Emulator (MAME) - www.mame.net
      MAME32 (now called MameUI)
      MameUI - www.mameui.info
      Ootake - www.ouma.jp/ootake
      VirtuaNES - virtuanes.s1.xrea.com:8080
      AppleWin - applewin.berlios.de
      Handy - handy.sf.net
      VI Plug-in SVMotion (functionality included in VCenter 4.x)
      
      Development
      
        Linux/Win32
      GCC - gcc.gnu.org
      Free Pascal - www.freepascal.org
      RHIDE - www.rhide.com
      OpenJDK - openjdk.java.net
      SCons - www.scons.org
      Komodo Edit - www.activestate.com/komodo_edit
      Scintilla - www.scintilla.org
      Code::Blocks - www.codeblocks.org
      NetBeans - www.netbeans.org
      Eclipse - www.eclipse.org
      CodeLite - www.codelite.org
      
      
        Linux Only
      Anjuta - anjuta.sf.net
      KDevelop - www.kdevelop.org
        Win32 Only
      Dev-C++ - www.bloodshed.net
      DJGPP - www.delorie.com/djgpp
      Crimson Editor - www.crimsoneditor.com
      
      
        Text Editors
      
        Linux/Win32
      Nano - www.nano-editor.org
      Vim - www.vim.org
      Emacs - www.gnu.org/software/emacs
      
      
        Linux Only
      gedit - gedit.sf.net
Win32 Only
      Notepad++ - notepad-plus.sf.net
      
      
        Games
      
        Linux/Win32
      0A.D. - www.wildfiregames.com/0ad
      Abuse - abuse.zoy.org/
Angband - www.rephial.org
      Armagetron Advanced - www.armagetronad.net
      AssaultCube - assault.cubers.net
      (not entirely open source)
      Atomic Tanks (Atanks) - atanks.sf.net
      Barrage - lgames.sf.net/index.php?project=Barrage
      Battle for Wesnoth - www.wesnoth.org
      Battle Tanks - btanks.sf.net
      Blob Wars: Metal Blob Solid - www.parallelrealities.co.uk/projects/blobWars.php
      BZFlag - www.bzflag.org
      Chromium B.S.U. - www.reptilelabour.com/software/chromium
      Circus Linux! - www.newbreedsoftware.com/circus-linux
      DarkPlaces - www.icculus.org/twilight/darkplaces
      EDuke32 - www.eduke32.com
      Enigma - www.nongnu.org/enigma
      Extreme Tux Racer - www.extremetuxracer.com
      ezQuake - ezquake.sf.net
      Freedoom - www.nongnu.org/freedoom
      FooBillard - foobillard.sunsite.dk
      Frotz - frotz.sf.net
Gargoyle - www.ccxvii.net/gargoyle
      Globulation 2 - www.globulation2.org
      GLtron - www.gltron.org
      Goblin Hack - goblinhack.sf.net
      GPL Arcade Volleyball - gav.sf.net
      Hedgewars - www.hedgewars.org
      IceBreaker - www.mattdm.org/icebreaker
      Star Control 2: The Ur-Quan Masters - sc2.sf.net
      Frozen Bubble - www.frozen-bubble.org
      Lincity - lincity.sf.net
      Liquid War - www.ufoot.org/liquidwar
      MegaMek - megamek.sf.net
      Mirror Magic - www.artsoft.org/mirrormagic
Moria - www.beej.us/moria
      NetHack - www.nethack.org
      Neverball - icculus.org/neverball
      Nexuiz - www.alientrap.org/nexuiz
      OpenArena - www.openarena.ws
      OpenLieroX - openlierox.sf.net
      PokerTH - www.pokerth.net
      PrBoom - prboom.sf.net
      Project: Starfighter - www.parallelrealities.co.uk/starfighter.php
      Risk - jrisk.sf.net
      Rocks'n'Diamonds - www.artsoft.org/rocksndiamonds
      SolarWolf - www.pygame.org/shredwheat/solarwolf
      
      SuperTux - supertux.berlios.de
      Tile World - www.muppetlabs.com/~breadbox/software/tworld
      Tremulous - www.tremulous.net
      Warmux - www.gna.org/projects/warmux
      Warzone 2100 Resurrection - www.wz2100.net
      Wolfenstein 3-D Redux - wolf3dredux.sf.net
      wxSand - www.piettes.com/fallingsandgame
      XBill - www.xbill.org
      X-Moto - xmoto.tuxfamily.org
      XWelltris - xnc.dubna.su/xwelltris
      Zod Engine - zod.sf.net
      
      
        Linux Only
      Atlantik (no longer maintained)
      Blob Wars: Blob and Conquer - www.parallelrealities.co.uk/projects/blobAndConquer.php
      GTetrinet - gtetrinet.sf.net
      KDE Games - www.kde.org/kdegames
      Kollision - games.kde.org/game.php?game=kollision
      Koules - www.ucw.cz/~hubicka/koules/English/koules.html
      Pingus - pingus.seul.org
      PySol - www.pysol.org
      Random Shooter - www.parallelrealities.co.uk/projects/randomShooter.php
      Virus Killer - www.parallelrealities.co.uk/projects/virusKiller.php
      
      
        Win32 Only
      Artificial Planet -  aiplanet.sf.net
      
Servers/Server
        Utilities
      
        Linux/Win32
      Apache HTTP Server - httpd.apache.org
      Apache Tomcat - tomcat.apache.org
      Apache Derby - db.apache.org/derby
      Squid - www.squid-cache.org
      MySQL - www.mysql.com
      MySQL Administrator - www.mysql.com/products/tools/administrator
      phpMyAdmin - www.phpmyadmin.net
      BIND DNS Server - www.isc.org/sw/bind
      Firebird - www.firebirdsql.org
      FlameRobin - www.flamerobin.org
      SQuirreL SQL - www.squirrelsql.org
      rsync - www.samba.org/rsync
      SQLite Database Browser - sqlitebrowser.sourceforge.net
      
        Linux Only
      Samba - www.samba.org
      OpenSSH - www.openssh.com
      Openfiler - www.openfiler.com
      vsftpd - vsftpd.beasts.org
      ProFTPD - www.proftpd.org
      PXELINUX - syslinux.zytor.com/wiki/index.php/PXELINUX
      Dnsmasq - www.thekelleys.org.uk/dnsmasq/doc.html
      
      
        Email Clients
      
        Linux/Win32
      Mozilla Thunderbird - www.mozilla.org/products/thunderbird
      YPOPs! - www.ypopsemail.com
      MrPostman - mrpostman.sf.net
      
      
        Linux Only
      Evolution - www.gnome.org/projects/evolution
      
      
        Graphics
      
        Linux/Win32
      Sodipodi (replaced by Inkscape)
      Gimp - www.gimp.org
      MyPaint - mypaint.intilinux.com
      Pngcrush - pmt.sf.net/pngcrush
      Inkscape - www.inkscape.org
      XSane - www.xsane.org
      Cornice - wxglade.sf.net/extra/cornice.html
      Pencil - www.pencil-animation.org
      ImageMagick - www.imagemagick.org
      Luminance HDR - qtpfsgui.sf.net
      
      
        Linux Only
      Evolvotron - www.bottlenose.demon.co.uk/share/evolvotron
      Comix (development halted)
      MComix - mcomix.sf.net (maintained
      version of Comix)
      feh - linuxbrit.co.uk/feh
      KolourPaint - www.kolourpaint.org
      Fotoxx - kornelix.squarespace.com/fotoxx
      Kooka (no longer maintained)
      Skanlite
      Xara Xtreme - www.xaraxtreme.org
      
      
        Win32 Only
      PNGShot - pngshot.sf.net
      Ascgen dotNET (ascgen2) - ascgendotnet.jmsoftware.co.uk
      CDisplayEx - cdisplayex.sf.net
      
      Networking/Security
      
        Linux/Win32
      Nmap - www.insecure.org/nmap
      GNU Privacy Guard (GPG) - www.gnupg.org
      Ipcheck.py (functionality is built into Tomato firmware)
      Ethereal (replaced by Wireshark)
      Wireshark - www.wireshark.org
      TightVNC (forked to TigerVNC)
      TigerVNC - www.tigervnc.org
      Clam AntiVirus - www.clamav.net
      PuTTY - www.chiark.greenend.org.uk/~sgtatham/putty
      WPA Supplicant - hostap.epitest.fi/wpa_supplicant
      Angry IP Scanner - www.angryziber.com/ipscan
      ntop - www.ntop.org
      Mozilla Firefox - www.mozilla.org/products/firefox
      cURL - curl.haxx.se
      Ettercap - ettercap.sf.net
      OpenSSL - www.openssl.org
      ophcrack - ophcrack.sf.net
      ipcalc - www.jodies.de/ipcalc
      Hyperic - www.hyperic.com
      John the Ripper - www.openwall.com/john
      wol - www.sf.net/projects/wake-on-lan
      Steghide - steghide.sf.net
      BitPim - www.bitpim.org
      Snort - www.snort.org
      
        Linux Only
      Tripwire - www.tripwire.org
      rdesktop (replaced by FreeRDP)
      NdisWrapper - ndiswrapper.sf.net
      FreeNX - freenx.berlios.de
FreeRDP - www.freerdp.com
      Cheops-ng - cheops-ng.sf.net
      Asterisk - www.asterisk.org
      TrixBox (Asterisk@Home) - asteriskathome.sf.net
      Knowlan - www.enderunix.org/knowlan
      (alternative: arpscan)
      whois - www.linux.it/~md/software
      Tomato Firmware - www.polarcloud.com/tomato
      PowerTOP - www.lesswatts.org/projects/powertop
      Galeon (replaced by Epiphany)
      OpenIPMI - openipmi.sf.net
      Kismet - www.kismetwireless.net
      Zenoss - www.zenoss.com
      ScanSSH - www.monkey.org/~provos/scanssh
      w3m - w3m.sf.net
      Remmina - remmina.sf.net
Seahorse - projects.gnome.org/seahorse
      Sleuth Kit (and Autopsy) - www.sleuthkit.org
OSSEC - www.ossec.net
      OpenVAS - www.openvas.org
      
        Win32 Only
      Windows Privacy Tools (WinPT) - winpt.sf.net
      WinPcap - www.winpcap.org
      ClamWin Antivirus - www.clamwin.com
      Program Killer - progkill.sf.net
      Blat - www.blat.net
    
Mac OS X Only
      OSXvnc - www.sf.net/projects/osxvnc
      
      
        Web Development
      
        Linux/Win32
      Nvu (replaced by KompoZer)
      KompoZer - www.kompozer.net
      (perhaps replaced by BlueGriffon)
      Linklint - www.linklint.org
      Bluefish - bluefish.openoffice.nl
      
      Shells/Terminals
      
        Linux Only
      Eterm - www.eterm.org
      Bash - www.gnu.org/software/bash/bash.html
      Konsole - konsole.kde.org
      ttyrec - 0xcc.net/ttyrec/index.html.en
      YaKuake - yakuake.uv.ro
      Screen - www.gnu.org/software/screen
      cool-retro-term - https://github.com/Swordfish90/cool-retro-term
      
        Win32 Only
      Cygwin - www.cygwin.com
      Poderosa - en.poderosa.org
      
      Screen Savers
      
        Linux/Win32
      electric sheep - www.electricsheep.org
      
      
        Linux Only
      XScreenSaver - www.jwz.org/xscreensaver
      ASCIIQuarium - www.robobunny.com/projects/asciiquarium/html
      
      Win32 Only
      Really Slick Screensavers - www.reallyslick.com
      ZMatrix - zmatrix.sf.net
      
      Distributed Computing
      Win32 Only
      SETI Driver (no longer appears to be active)
      SETI Spy (no longer updated, sadly the author passed away. my
      condolences)
      
      
        Science
      
        Linux/Win32
      Stellarium - www.stellarium.org
      Celestia - www.shatters.net/celestia
      
      
        Linux Only
      KStars - edu.kde.org/kstars