Implementing a resizable textarea?

Question

How does Stackoverflow implement the resizable textarea?

Is that something they rolled themselves or is it a publicly available component that I can easily attach to

Answer 1

StackOverflow uses a jQuery plugin to accomplish this: TextAreaResizer.

It's easy enough to verify this - just pull the JS files from the site.

Historical note: when this answer was originally written, WMD and TextAreaResizer were two separate plugins, neither one of which was authored by the SO Dev Team (see also: micahwittman's answer). Also, the JavaScript for the site was quite easy to read... None of these are strictly true anymore, but TextAreaResizer still works just fine.