Ask HN: what kind of TextArea is used by HN?

I want something exactly like HN text area where formatting is retained like line breaks, auto-link detection. I tried using TinyMCE and one mentioned here(http://www.dynamicdrive.com/dynamicindex16/richtexteditor/index.htm)

The problem is that on the backend they don't send the HTML formatting

I am very new to web dev and dont have much idea about where to look for resources as well. Please help!