This is rough: There are many types of popular software that aren't that big of a deal to re-implement. You could look at examples of popular software and think "This blows, I'll re-invent it". With care, dedication, and careful management, you could do it. This doesn't mean people will switch from the popular established software, but you could do it.
Web browsers are not one of these. Way too complicated, largely due to the complicated and changing DOM and JS specs.
Web browsers are not one of these. Way too complicated, largely due to the complicated and changing DOM and JS specs.