- webdriverjs (code) - created before official client, still often in use
- wd (code) - created before official client was released, still maintained and still often in use
- selenium-webdriver (code) - official release, calls itsself WebDriverJs, which causes confusion with the webdriverjs node module mentioned above.
- protractor (code) - is built on top of selenium-webdriver and adds functionality for AngularJS applications.
I choose to use the wd client because