Error 404 is generated by Apache server and it means that the website does not work. To be more precisely, it means “Page Not Found”. I bet that you have already seen this error message. What is it so important and why does Mozilla want to change something released to error 404?
Before the website will be displayed on your computer, the web browser application sends request to the server. As the response, your computer receives HTTP header with a status. In most cases, i.e. when everything works, this header contains status “200“. Therefore, your web browser knows that the page can be loaded and displayed. However, server can send also a header with “404“ code. The first “4“ means that this is an error caused by a user, i.e. the wrong address is used or the requested site does not exist any longer. The “0“ means that this is syntax error and the last “4“ means that the requested target does not exist. So, this is more clear now. However, why do I write about 404 error today?
Mozilla wants to remove from Firefox the function which displays 404 error information.
This may be strange, but they have quite good idea. How will it work? If Mozilla Firefox browser receives the 404 error message from website server, then it will open an archived version of this site. For this purpose, Internet Archive data base with the most popular websites will be used. Mozilla claims that it is better to see old cached version of a site than to watch an error message. This is great information for Internet users, because they will have always access to requested information. This is obvious that people are angry when they can not open the favorite site because of server failure. I think that this feature will be also appreciated by administrators, because they will be have more time to repair servers. Of course, all this kind of failures are being fixed as soon as possible, but it is simpler when user do not complain.
At this moment, this functionality is available only in Mozilla Firefox Test Pilot program.
I hope that the final version of this feature will well designed and thought out. At first, a user should be informed that the displayed site is cached version and it can contain old data. Also, it should be possible to disable this feature, because people are also testing web sites and they want to know if the site is available or not.