Selenium Tool

I need some details about selenium tool this is an open tool use for web testing , if some one has used it please help me with some more details like how to use , scripts , and generalization .
Thanks.

Selenium is a test tool for web applications. Selenium tests run directly in a browser, just as real users do. And they run in Internet Explorer, Mozilla and Firefox on Windows, Linux, and Macintosh. No other test tool covers such a wide array of platforms.

Browser compatibility testing. Test your application to see if it works correctly on different browsers and operating systems. The same script can run on any Selenium platform.

System functional testing. Create regression tests to verify application functionality and user acceptance.

Selenium Tool has 3 modules: Core, IDE and Remote Control

[B]Selenium Core:[/B] Basically selenium core runs through browser but for the installation one must have write access to the web server since the tests are run from web server, since it uses JavaScript and DHTML to execute and simulate the behavior of the real end user.

[B]Selenium IDE:[/B] It is an integrated development environment for Selenium tests. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests. Selenium IDE includes the entire Selenium Core, allowing you to easily and quickly record and play back tests in the actual environment that they will run.

So Selenium IDE can be used as a recording tool and then the recorded scripts can be exported in any of the languages which Selenium-RC supports.

[B]Selenium Remote Control:[/B] is a test tool that allows you to write automated web application UI tests in any programming language against any HTTP website using any mainstream JavaScript-enabled browser.

It uses HTTP's Get and Post methods, this means that you can use any programming language which can make http requests.
So are the options available, it supports executing tests in more than 7 languages (Java, .Net, Perl, Python, Ruby, PHP, JavaScript).