Microsoft, the only software vendor who is permitted to fix vulnerabilities in Windows XP, has stopped fixing them.
Google has also announced that it will end Windows XP support for its Chrome browser in April 2016.
According to Mozilla, Windows XP users of Firefox are geographically and linguistically diverse, and make up more than one tenth of the entire Firefox user population.
However, Mozilla believes that offering the remaining Windows XP users support can protect them from online security "dangers".
In the future, maybe Firefox will start testing nastygrams to pop up at Windows XP user base when they start their next browsing session: "Did you know that your operating system is older than many Mozillians?", "It appears as though you are accessing the Internet using a close relative of the abacus", "We have determined that this is the email address of your closest Linux User Group who can help you secure your computer".