Are you a website developer, you really need some tools that can easily
help you doing your work easier, i write this because i still see peoples
that are having problems and not knowing where to start to resolve them.
Firefox is a good web browser, that will help you a lot, including error console,
i really recomand it,even if your customers are using only Internet Explorer,
is a good start, there are also the plugings that may really help you, those
are: FireBug(All tabs are really usefull,the tab NET where
you are seeing the missing web sites components those reds,having a 404),
SenSO, YSlow, if you have Nagios as system to monitorize your services, also
Nagios Add-on it’s also usefull, playing with ajax on all browser may be
messy, i did have a lot of problems when use it, but the most help in developing
will be from Firefox.