Bootstrap 3 still supports IE8. You can still use Bootstrap 3, or even Bootstrap 2.
But it makes little sense to develop new tools that support IE8 at this point. By the time Bootstrap 4 is released (probably many months from now), IE8 usage will be even lower.
Further, since it's solely responsible for so many edge cases, polyfills, and hacks, it doesn't hurt to gently push for its demise. Even Microsoft is trying.
Well why in the name of all good design did Microsoft not put out a version of IE9 for Windows XP while it was still supported? That would made everything so much simpler, including for them -- after all, they have to worry about IE8 just like the rest of us, XP or no.
Jesus, I don't mean for me. I haven't touched XP in years, and have very rarely used any Windows OS for the past 5-6 years.
But there are millions of people in developing countries who can't afford to upgrade, or don't know how. Have you considered that? This is not a first-world problem.
Why not accommodate those users? MS doesn't have to support the OS itself, but think of how much trouble it could save developers around the world -- inside of Microsoft and out -- if all these XP machines were automatically upgraded to IE9.
Uh, when was the last time you saw XP on a new machine - from Google Analytics on a UK retail site I'm getting 2.4% of users on XP this month, equivalent month in 2013 was 6.5%, in 2012 was 12.4%, in 2011 21%, 2010 34% - that's basically halving each year for the last 3 years.
Yeah, this is because your users are mostly in the U.S. or Western Europe. It's a different story elsewhere in the world (although even those countries are slowly moving off of XP).
But it makes little sense to develop new tools that support IE8 at this point. By the time Bootstrap 4 is released (probably many months from now), IE8 usage will be even lower.
Further, since it's solely responsible for so many edge cases, polyfills, and hacks, it doesn't hurt to gently push for its demise. Even Microsoft is trying.