If you use more than one browser including safari. You can easily change your default browser with safari and handle your all browser easily. Whenever you install new browser and you don’t keep more attention, definitely your new installed browser is set as a default browser.

Default browser –which web browser(Firefox, Google chrome, internet explorer- 6, 7, 8, opera, Safari or any other web browser) will be open, when you open an Internet shortcut or any html file or click any internet related link , if you have more than one web browser installed on your computer.

Try some interesting thing, only safari browser gives some more advance option for changing default browser which installed on your computer on real time. 

Open safari and click on edit in menu bar then click on preferences… , Select General tab key and chose your default browser (list display only installed browser)

www.example.com
Type only example in address bar / Location bar then press Ctrl + Enter and you will get www. & .com automatically
Work with – Firefox , opera , Internet Explorer -6,7,8 , Google Chrome , Safari

www.example.net
Type only example in address bar / Location bar then press  Shift + Enter and you will get www. & .net automatically
Work with – Firefox

www.example.org
Type only example in address bar / Location bar then press Ctrl + Shift + Enter and you will get www. & .org automatically
Work with – Firefox

3.Select the Advanced tab.
4.In the left pane, select History.
5.And Click “Empty now” to delete all cached content from your disk.
6.Click OK.

Note: If you Check “Empty on exit” to delete all cached automatically every time you exit Opera.