Desktop Applications
Communication      Email Client = [WWW] Thunderbird
             Compare to: Microsoft Outlook
      IRC Client = [WWW] X-Chat 2, [WWW] Bersirc, [WWW] HydraIRC
            Compare to: Unknown
      Universal Instant Messaging Client = [WWW] Pidgin (formerly Gaim), [WWW] Miranda IM
            Compare to: Trillian
      Web browser = [WWW] FireFox
Compare to: Microsoft Internet Explorer
      Voice Over IP = [WWW] OpenWengo
Compare to: Skype
Engineering      EDA = [WWW] KiCad
   Compare to: Eagle
EducationalLearning Games = [WWW] Childsplay
Compare to: Unknown
Planetarium = [WWW] Stellarium
Compare to: Unknown
      Space Simulator = [WWW] Celestia
Compare to: Unknown
      Flight Simulator = [WWW] FlightGear
Compare to: MS Flight Simulator
      Typing Tutor = [WWW] Tux Typing
Compare to: Unknown
      Beginner Drawing Program = [WWW] Tux Paint
Compare to: KidPix
FinancialPersonal Accounting = [WWW] HomeBank, [WWW] Grisbi, [WWW] jGnash
Compare to: Quicken, Microsoft Money
      Accounting: [WWW] TurboCash
Compare to: Intuit Quickbooks
      Monitoraggio Finanziario = [WWW] MFbyAS
Compare to: Unknown
Productivity
Database (Desktop) = [WWW] OpenOffice (Base)
Compare to: Microsoft Office (Access)
      Desktop Publishing = [WWW] Scribus
Compare to: Microsoft Publisher
      Mind Mapping = [WWW] FreeMind
Compare to: Mindjet MindManager, Inspiration
      PDF creator = [WWW] PDF Creator
Compare to: Adobe Acrobat
      Presentation = [WWW] OpenOffice (Impress)
Compare to: Microsoft Office (Powerpoint)
      Spreadsheet = [WWW] OpenOffice (Calc)
Compare to: Microsoft Office (Excel)
      Word Processor = [WWW] OpenOffice (Writer), [WWW] AbiWord
Compare to: Microsoft Office (Word)
      Scientific Word Processor = [WWW] Lyx (Latex gui frontend)
 Compare to: Scientific Word
      Notepad Replacement = [WWW] Notepad2, [WWW] Notepad++, [WWW] SciTE
Compare to: Notepad
Management Gantt chart = [WWW] GanttProject
 Compare to: Microsoft Project
      Project management = [WWW] Planner, [WWW] OpenWorkbench
Compare to: Microsoft Project
      Report Creator = [WWW] JasperReports
 Compare to: Crystal Reports      Analisi dei processi = [WWW] APbyAS
Compare to Unknown
      Gestione Attività = [WWW] PMbyAS
Compare to Microsoft Project      Team Collaboration = [WWW] Mindquarry
Compare to Microsoft SharepointMisc      Animal Shelter Manager = [WWW] Animal Shelter Manager
Compare to: Unknown   
   Virtual PC emulator = [WWW] Bochs, [WWW] Qemu
  Compare to: VMware, Microsoft Virtual PC      Linux environment = [WWW] Cygwin
Compare to: Unknown
      Recipe Manager = [WWW] Gourmet Recipe Manager
 Compare to: Unknown
      Screen Saver = [WWW] Really Slick Screensavers
 Compare to: Unknown
      Language Translation tool = [WWW] OmegaT
 Compare to: Unknown
      Countdown Timer = [WWW] CookTimer
 Compare to: Unknown
      Application Launcher = [WWW] Launchy
Compare to: Unknown
Multimedia
3D    *
3D Animation = [WWW] Blender, [WWW] Wings 3D
Compare to: Alias Maya
      3D Graphics = [WWW] POV-Ray
Compare to: Unknown
      3D Game Development Kit = [WWW] Crystal Space, [WWW] Ogre3d
  Compare to: Unknown
Audio      Audio Editing = [WWW] Audacity
Compare to: Adobe Audition
      Audio Player = [WWW] Coolplayer, [WWW] Zinf
Compare to: WinAMP, Windows Media Player
      Drum Machine = [WWW] Hydrogen
Compare to: Unknown
      MP3 Ripper = [WWW] CDex
Compare to: Exact Audio Copy
      Volume normalizer = [WWW] MP3Gain
Compare to: Unknown
Drawing  
    Diagram Editor = [WWW] Dia
Compare to: Microsoft Visio      Image Editing = [WWW] Gimp, [WWW] Paint.NET               
   Compare to: Adobe Photoshop, Corel Paint Shop
      Vector Drawing = [WWW] Inkscape, [WWW] SodipodiOther    *
      HTPC/PVR Media Centre = [WWW] MediaPortal
  Compare to: Microsoft Media Centre Edition (MCE), Showshifter, SageTV
      Media Player = [WWW] VLC media player
Compare to: Windows Media Player, PowerLink PowerDVD, Intervideo WinDVD
      Web Design = [WWW] Nvu
 Compare to: Microsoft Frontpage, Macromedia Dreamweaver
Video      Internet TV platform = [WWW] Democracy Player
 Compare to: iTunes, FireAnt
      Video Capture = [WWW] VirtualDub
 Compare to: Sorenson Squeeze
      Video MPEG-4 codec = [WWW] ffdshow, [WWW] XviD
Compare to: DivX
      Video Editing = [WWW] Jashaka, [WWW] Avidemux,
 Compare to: Adobe After Effects, Pinnacle Studio, Apple Final Cut
Security
      802.1x client (EAP-TTLS) = [WWW] SecureW2
Compare to: Unknown
      Anti-Spyware = [WWW] Winpooch, [WWW] Spybot Search&Destroy (not OpenSource, but FreeWare)
Compare to: Unknown
      Anti-Virus = [WWW] ClamWin
Compare to: Unknown
      Encryption = [WWW] Truecrypt
 Compare to: Win Zip?
      Network protocol analyzer = [WWW] Wireshark
Compare to: Sniffer
      Password strength testing = [WWW] Ophcrack 2
 Compare to: LOphtCrack
      Password safe = [WWW] KeePass Password Safe, [WWW] Password Safe
Compare to: Unknown
      VPN client = [WWW] OpenVPN client GUI for Windows
Compare to: Cisco VPN client, Nortel VPN client
Software Development      Framework/Platform = [WWW] Mono
Compare to: Microsoft .NET Framework, Java      Integrated Development Environment = [WWW] Eclipse, [WWW] SharpDevelop, [WWW] Code::Blocks, [WWW] Lazarus IDE, Free Pascal
Compare to: Microsoft Visual Studio, Borland IDE    
  Windows Installer = [WWW] Nullsoft Scriptable Install System, [WWW] Inno Setup
Compare to: InstallShield, Microsoft InstallerUtilities      BitTorrent client = [WWW] Azureus, [WWW] BitTorrent Client
Compare to: Unknown
      File compression = [WWW] 7-Zip
   Compare to: WinZip
      FTP Client = [WWW] Filezilla FTP client
 Compare to: SmartFTP, BulletProof FTP
      Statistics on Disk usage = [WWW] WinDirStat
Compare to: Unknown
      P2P file-sharing = [WWW] Shareaza, [WWW] Ares
Compare to: Napster
      Remote Administration = [WWW] UltraVNC
Compare to: PCAnywhere, GoToMyPC.com, Windows Remote Desktop
      Process Usage Analysis = [WWW] Process History
Compare to: Unknown
      Daphne, process list & manager = [WWW] Daphne
Compare to: Windows task manager
Server ApplicationsDatabase      Database server = [WWW] Firebird, [WWW] MySQL, [WWW] PostgreSQL
Compare to: Microsoft SQL server, Oracle databaseFile Server
      FTP server = [WWW] Filezilla FTP server
 Compare to: UnknownMessaging
      Email server = [WWW] hMailServer
Compare to: Microsoft Exchange server, Novell GroupWise server      Instant messaging server = [WWW] Jive Messenger
  Compare to: Novell GroupWise Messenger
Security      Intrusion Detection System (IDS) = [WWW] Snort
Compare to: Unknown
      VPN server = [WWW] OpenVPN
Compare to: Cisco VPN
Web
Application server = [WWW] JBoss
Compare to: BEA Weblogic, IBM Websphere
      Rich Internet Application Server = [WWW] OpenLaszlo
 Compare to: Macromedia Flex
      Statistics Generator = [WWW] AWStats
Compare to: Unknown
      Web server = [WWW] Apache
Compare to: Microsoft Internet Information Services (ISS)+ http://www.linuxrsp.ru/win-lin-soft/table-eng.html