1. Download Selenium from openqa.org. The latest release of Selenium as of this writing is 0.6.
2. Unzip selenium-0.6.zip and cd into the selenium-0.6 directory.
3. Move or copy the selenium sub-directory somewhere under the DocumentRoot of your Apache server.
That's it -- you have a working Selenium installation!
Here's a screencast which contains the above steps. As I said, it took me 32.78 seconds to do all these things, and almost of all of that time was taken by the download of the zip file: QuickTime format and AVI format.
Now that you've installed Selenium, you might wonder what's your next step. Easy: open the following URL in a browser: http://www.yoursite.com/selenium/TestRunner.html ; you'll see the default test suite that is used to test Selenium itself. Click on the All button in the Control Panel frame on the right, and all the tests in the suite will be executed one by one. If you want to run only a specific test, click on that test name, then click Selected instead of All in the Control Panel.
Again, pictures are worth many words, so here's a screencast of running the default test suite in Firefox: QuickTime format (warning: 28 MB file) and AVI format. Note that some tests involving pop-up windows are failing, because Firefox doesn't allow pop-ups.
Next question: how do you write your own test? A Selenium test is basically an HTML file containing a table with Selenium commands and assertions. The default tests and test suite are in
For more introductory articles on Selenium, see the Getting Started section of the OpenQA Selenium Wiki.
Update: At Jason Huggins's suggestion, here is a screencast that shows the whole enchilada -- downloading Selenium, installing it and running the default test suite. The whole thing takes a mere 2 minutes and 12 seconds: Quicktime format (warning: 36 MB file), Windows Media format (1 MB file), AVI format (8 MB file).