I found IE7.js on an open-source project site several months ago. The link is below. It has 1,820 active users, and continues to receive designation as a high activity project. IE7.js was written by Dean Edwards.
Perhaps this will be helpful to those long-suffering souls who toil away, supporting Internet Explorer 5 or 6. Yes, some remain, although Microsoft itself no longer supports IE 5 or IE 6.
Possible Use Case in the Wild
I have seen active, important websites that remain in the Internet Explorer 4 era. A rather notable example of such is the (public-facing) website of the largest R&D organization for rare earth elements mining and extraction in the world, Baotou Rare Earth Research Institute. Navigate to the site. View this distinctive IE icon, labeled “IE 4.0”. It is surrounded by festive insignia rarely seen elsewhere. I thought it was lovely.
For an additional treat, click on the logo (on the Baotou website). You will see this page, which seems quite security aware! [translated, emphasis mine]
Internet police. Hint: In order to maintain the legitimacy of Internet sites, if Baotou is not the site of record, please click on the black sites button, to report to public security organs.
* There is an English-language Baotou Research site, but it does not feature the IE 4 logo.
Upgrade MS IE5.5 and IE6 to be compatible with MS IE7.
<!--[if lt IE 7]><script src="http://ie7-js.googlecode.com/svn/version/2.1(beta4)/IE7.js"></script><![endif]-->
Upgrade MS IE5.5 – IE7 to be compatible with MS IE8.
<!--[if lt IE 8]><script src="http://ie7-js.googlecode.com/svn/version/2.1(beta4)/IE8.js"> </script><![endif]-->
You do not need to include IE7.js if you are using IE8.js
Upgrade MS IE5.5 – IE8 to be compatible with modern browsers!
<!--[if lt IE 9]><script src="http://ie7-js.googlecode.com/svn/version/2.1(beta4)/IE9.js"></script><![endif]-->
You do not need to include IE7.js or IE8.js if using IE9.js
Medicine for your IE6 PNG headache!
Postscript: Several bonus Internet Explorer fixes are aggregated as IE-7 Squish!, to squish IE bugs, of course.