Install
If you use homebrew (which I recommend), you can install selenium using:
brew install selenium-server-standalone
Running
updated -port port_number
To run selenium, do: selenium-server -port 4444
selenium-server -port 4444
For more options: selenium-server -help
selenium-server -help
Mac already has Python and a package manager called easy_install, so open Terminal and type
easy_install
sudo easy_install selenium
To use the java -jar selenium-server-standalone-2.45.0.jar command-line tool you need to install a JDK.You need to download and install the JDK and the standalone selenium server.
java -jar selenium-server-standalone-2.45.0.jar