Why IE Rules the Intranet
Mozilla CEO: Why we’re still shunned by corporate IT: This article is year old, but the point still holds true.
While many IT directors do allow the open-source browser to be used on company time, those who don’t are often held back by the proprietary technologies employed on their intranets.
“Enterprises have intranets that only work with (Microsoft’s) IE,” Baker said. “We can’t fix their intranet.”
I built my last intranet specifically to be Firefox-friendly, strictly so I could use the development tools in Firefox (Firebug and the Web Developer toolbar).