If the only issue is IE 6, 7 and 8 marketshare, then the question becomes: how long will IE8 have a sizable portion of the market. Here's a graph of the browser

If the only issue is IE 6, 7 and 8 marketshare, then the question becomes: how long will IE8 have a sizable portion of the market. Here's a graph of the browser market over the last 3 years (typical disclaimer about lies, damn lies and statistics, and measure your own traffic, etc.) http://gs.statcounter.com/#browser_version_partially_combined-ww-monthly-201003-201303 http://gs.statcounter.com/#browser_version_partially_combine... Assuming the above graph is relatively close to the truth, IE8 is around 10% of the worldwide marketshare. So, the question is: when does a library like jQuery drop support? 10% marketshare, 5%, 2%, 1%? At what point is the overhead outweigh the benefits? Obviously there are some developers who need to support IE7 (for example), regardless of the overall market. I personally don't think that should be the approach for tools like jQuery: time is valuable, and they should target the largest possible market possible.