1. Download Xcode
This can be found at the Apple Developer site, on your Mac OS X installation CDs/DVD, or in the Mac App Store.
2. Install Command Line Tools for Xcode
Under Xcode:
Preferences -> Downloads -> Components -> Install 'Command Line Tools'
3. Accept the Xcode EULA
Either launch Xcode or run:
xcodebuild -license
4. Download and Install X11 (XQuartz)
5. Download and Install MacPorts
6. Update MacPorts
Note: Make sure Xcode is fully installed.
sudo port -v selfupdate
7. Install Putty
sudo port install putty
8. Run Putty
Type ‘putty’ into Terminal:
putty
This should open Putty in an X11 window.
9. Desktop Shortcut for Putty
cp /opt/local/bin/putty ~/Desktop/PuTTY