Simply, automatically and standards-compliantly make any external link open in a new window/tab.
There is a little gotcha when you’re writing standards compliant code, but still want off-site links to open in new windows. XHTML 1.0 Strict deprecated the use of the “target” attribute. Early versions of HTML5 also had this deprecation, but have since brought it back. In either case, making sure the target attribute is set on every off-site link can be tedious.
Enter jQuery.autoTarget for WordPress
Instead of going through the tedium of ensuring your target attributes are set, this jQuery plugin automatically scans all the links on a page, and sets the attribute for you (target=”_blank”) if the href attributes domain isn’t the same as the domain the page is served from. Just to sweeten the deal, it also sets any offsite link to have a class of “external-link”, so you can style offsite links in the manner of your choice. Easy-peasy. And it only weighs in at 272 bytes!
Just in case, the script does not touch any link that already has a target set, so if you’re already doing something with the target attribute, this won’t clobber your extant work.
Use of jQuery.autoTarget in Non-WordPress Sites
This is actually just wrapping my jQuery.autoTarget code in a WordPress plugin. You can grab the original jQuery.autoTarget jQuery plugin here.