Zack Smith did a post on his website about using TextMate’s URI links (at http://www.wallcity.org/2011/03/textmate-uri-links ). This prompted me to feel like checking to see which arbitrary strings would be followed from within the major browsers of Mac OS X. See for yourself: file:///Applications/iTunes.app/Contents/MacOS help://test vnc://127.0.0.1 ftp://127.0.0.1 smb://127.0.0.1 smb://127.0.0.1/myshare/my%20file.txt afp://127.0.0.1 afp://127.0.0.1/myshare/mydmg.dmg nfs://127.0.0.1 Note: The following command still stops HelpViewer.app from opening AppleScript: defaults write /System/Library/CoreServices/HelpViewer.app/Contents/Info NSAppleScriptEnabled -bool no