Once in a while I remind myself that I should create a list of some of my favorite freeware or open-source tools. Perhaps this will be a running list, but here it is, in no particular order!

Editors/File-Directory Comparison or Merge

  • Emacs (http://www.gnu.org/software/emacs/)
  • Vim (http://www.vim.org/)
  • PSPad (http://www.pspad.com/)
  • WinMerge (http://winmerge.org/)

IDE

  • Eclipse (http://www.eclipse.org/)

Encryption

  • TrueCrypt (http://www.truecrypt.org/)
  • GnuPG (http://www.gnupg.org/)

Security Tools (too many to list)

  • Packet Capture: Wireshark (http://www.wireshark.org/)
  • Vulnerability Scanning: Nessus (http://www.nessus.org)
  • PenTest toolkit: BackTrack (http://www.remote-exploit.org/backtrack.html)
  • Password Safe: KeePass (http://keepass.info)

Network Monitoring

  • Dave Plonka’s FlowScan (http://net.doit.wisc.edu/~plonka/FlowScan/)
  • flow-tools (http://www.splintered.net/sw/flow-tools/)
  • Nagios (http://www.nagios.org)

Disk Tools

  • Gnome Partition Editor aka GParted (http://gparted.sourceforge.net/)
  • JkDefrag (http://www.kessels.com/JkDefrag/)

Windows Registry Cleaner

  • CCleaner (http://www.ccleaner.com/)

Windows File Archiver

  • 7-Zip (http://www.7-zip.org)

FTP/SFTP/SCP/TFTP Client

  • Windows: FileZilla (http://filezilla-project.org/)
  • Mac OSX: CyberDuck (http://cyberduck.ch/)
  • tftpd32 (http://tftpd32.jounin.net/)

IM Client

  • Windows: Trillian (http://www.ceruleanstudios.com/)
  • Mac OSX: Adium (http://www.adiumx.com/)

Mind “mapping”

  • FreeMind (http://freemind.sourceforge.net/)

PDF Creation

  • CutePDF (http://www.cutepdf.com/Products/CutePDF/writer.asp)

Graphing (unidirected graphs)

  • GraphViz (http://www.graphviz.org/)

SSH/Terminal

  • PuTTY (http://www.chiark.greenend.org.uk/~sgtatham/putty/)
  • TermTerm/TeraTerm Pro

Firefox Plugins (see http://addons.mozilla.org)

  • AdBlock Plus
  • IE Tab
  • Greasemonkey

Astronomy

  • Stellarium (http://www.stellarium.org/)

Photography/Image Manipulation

  • Picasa (http://picasa.google.com/)
  • The GIMP (http://www.gimp.org/)
  • IrfanView (http://www.irfanview.com/)