Where can I find phpunit + selenium documentation?

Question

PHP

I am learning to write tests. Now engaged in functional. I read about Selenium, installed it, and wrote a couple of tests using phpunit (PHPUnit_Extensions_SeleniumTestCase, PHPUnit_Extensions_Selenium2TestCase). In this regard, several questions arose:
1. To write commands for WebDriver in PHP, use these two classes (PHPUnit_Extensions_SeleniumTestCase, PHPUnit_Extensions_Selenium2TestCase) in PHPUNIT? They have different API. Where can I find detailed documentation on all the methods of these classes (googled, looked at phpunit.de/, looked at tests for the methods of these classes). Not everything is there. And there are no examples on the Internet. Who thread them uses.
2. Found another library from facebook php-webdriver. As I understand it - a competitor?) There is also no detailed documentation on the methods. API is different from the first one.
3. Another one: php-webdriver-bindings
There is no documentation with methods. A few examples.
Questions 2:
1. Who uses what library? Which is better?
2. Does everyone have their own API or do they still implement some WebDriver methods and therefore you can look at the documentation on WebDriver methods?

Answer 1

Off topic of course.. But switch to Ruby )
Ruby is the most test-loving party ;)