Firefox can show your passwords unless you set a master password. Setting a master password then requires you to enter that password anytime any of your remembered passwords would be used. This is a convenience because it allows you to only have to remember one password, but it’s still not as convenient as not setting a master password and then not having to enter a password during your daily browsing, thus the majority of users follow this behavior.
You can then view the saved passwords in Firefox through Tools, Options… Click on the Security Tab, and then click on the Saved Passwords… button. A new window will pop up and you can see the list of saved passwords. Clicks the ‘Show passwords’ button to view the passwords, along with the URLs and user names.
If you do encounter a Master Password, you can use FireMaster to see if you’ll be able to crack it.
IE records your passwords and doesn’t show them, and you don’t have to set a master password to keep people from seeing those passwords easily. However, with Firefox on the machine, you can simply go to File, Import… and tell it to import passwords from IE. Wah-lah! Firefox’s weakness is IE’s weakness too.
You can also view the passwords in Google Chrome. Just go to Settings, Options. Click on the Personal Tab and then click on the Show Saved Passwords button.