These are my favorite free applications, covering a variety of categories, from simple utilities to complex development apps. All of these are truly free (freeware or free software or open source), not shareware or nagware.
| Category | Application Name | Windows | Mac | Linux | Android |
|---|---|---|---|---|---|
| .NET Analysis | Reflector | X | |||
| .NET Build | NAnt | X | |||
| .NET IDE | Microsoft Visual Studio Express Editions | X | |||
| .NET Unit Testing | NUnit | X | |||
| Anti-Virus | avast! | X | X | ||
| Anti-Virus | Microsoft Security Essentials | X | |||
| CD Mounting | Daemon Tools Lite | X | |||
| Continuous Integration | CruiseControl | X | |||
| Database | Microsoft SQL Server Express | X | |||
| Disk Analysis | WinDirStat | X | |||
| E-Mail Client | Mozilla Thunderbird | X | X | X | |
| Encryption | TrueCrypt | X | X | X | |
| File Compression | 7-Zip | X | |||
| File Management | FreeCommander | X | |||
| File Synching | Dropbox | X | X | X | X |
| File Unlocking | Unlocker | X | |||
| FTP Client | FileZilla | X | X | X | |
| Hard Disk Analysis | DiskBench | X | |||
| Hex Editor | Free Hex Editor Neo | X | |||
| Icon Creator | Imagicon | X | |||
| Image Editor | Paint.NET | X | |||
| Instant Messenger | Pidgin | X | X | X | |
| Instant Messenger | Trillian | X | X | X | |
| Linux Look and Feel | Cygwin | X | |||
| Media Player | VLC Media Player | X | X | X | |
| MIDI Editing | Anvil Studio | X | |||
| Network Analysis | Fiddler | X | |||
| Network Analysis | Wireshark | X | X | X | |
| Office | LibreOffice | X | X | X | |
| Operating System | Ubuntu (GNU/Linux) | ||||
| Password Management | KeePass | X | X | X | X |
| PDF Viewer | Foxit Reader | X | X | ||
| PDF Writer | CutePDF Writer | X | |||
| Photo Editor | GIMP | X | X | X | |
| Remote Desktop Client | mRemoteNG | X | |||
| Scanner | FreeKapture | X | |||
| Screen Recording | CamStudio | X | |||
| Secure Connection | Copssh | X | |||
| Sound Editor | Audacity | X | X | X | |
| Source Control Client | TortoiseSVN | X | |||
| Source Control Server | CollabNet Subversion Edge | X | |||
| SQL Server Management Studio Plugin | dbForge SQLComplete | X | |||
| Text Editor | Notepad++ | X | |||
| Text Editor | Programmer's Notepad | X | |||
| Textfile Change Watcher | Tail for Win32 | X | |||
| Textfile Comparison | WinMerge | X | |||
| Twitter Client | TweetDeck | X | X | X | X |
| Virtualization | Oracle VirtualBox | X | X | X | |
| VNC | RealVNC | X | X | ||
| VPN Client | ShrewSoft VPN | X | X | ||
| Web Browser | Google Chrome | X | X | X | |
| Web Browser | Mozilla Firefox | X | X | X |
