How to get browser name, version and operating system detail in selenium

We can get the browser name, version and operating system name and version with the following commands in selenium RC.
Below code is tested in Mozilla Firefox
Browser Name 

System.out.println(selenium.getEval("navigator.appCodeName;"));

Mozilla

Browser version 

System.out.println(selenium.getEval("navigator.appVersion;"));

5.0 (Windows; en-US)

Browser and Operating system detail

System.out.println(selenium.getEval("navigator.userAgent;"));

Result.

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 (.NET CLR 3.5.30729)

String browser = selenium.getEval("navigator.userAgent");
if (browser.contains("Firefox")  || browser.contains("Chrome")) {