do you keep IE in mind when develop a website ?

Question

here's what bugging me, for me IE isnt the best enviroment for modern website specially the pre-IE9, well even some people still mad with IE11. i know phrase like "people no longer use IE" is pretty popular, but i've seen in some work enviroment IE is still being used. mainly because its shipped with the OS (i think). or some peope just dont bother to install other browsers, since they dont use them a lot. but even if the number of users are small there are people who still use IE for their "internet needs", and they could possibly visit your web.
so do you ever consider IE when developing a web ?
what about other smaller yet well known browser like Opera ?
as for me. i almost completely throw ie out of consideration, depend on the project i working on.

Answer 1

Add polyfill for ie support, polyfill does not add overhead on other new browsers, since it does not add extra codes there. So it wouldn't affect the new browser performance.
And also add vendor prefix for the css selectors.