How to detect which type of browser is being used
(and browser capabilities)

It is actually incredibly easy to establish which browser is being used using JavaScript. It is simply:

navigator.appName

This typically returns 'Microsoft Internet Explorer', 'Netscape' or the name of some other browser if it is something other than Internet Explorer or Netscape.

So your browser is:

However, knowing the type of browser is not as useful as knowing what features the browser supports. The following table lists some of the common data items to test:

document.images	Use to test if the browser supports images. Defined if the browser supports images, undefined if it does not support images.
document.layers	Use to test if the browser supports layers. Defined if the browser supports layers, undefined if it does not.
document.all	Use to test if the browser supports Dynamic HTML (DHTML). Defined if the browser supports DHTML, undefined if it does not.
document.frames	Use to test if the browser supports frames. Defined if the browser supports frames, undefined if it does not.
document.filters	Use to test if the browser supports Microsoft transition effects. In practise only Internet Explorer supports transition effects.

For example:

if (document.images)
  document.write('Browser supports images')
else
  document.write('Browser does not support images);