In short, cURL is a Swiss Army knife on steroids for data transfers over TCP/IP and is for just about any OS you can think of, which includes the usual suspects -- OS X, , -- as well as many others including Amiga, Syllable, VMS and z/OS.
So, way back in those heady days when we were all slowly but certainly losing our shirts, you could post a tweet using a command in the form of:
curl -u username:password -d status="I had a chicken sandwich for lunch" http://twitter.com/statuses/update.xml
This method, using basic authentication, worked great and it was easy to arrange, for example, for your machines to use Twitter as a messaging system to let you know when they had problems or completed something. But on Aug. 30, 2010, Twitter stopped allowing access via basic authentication and switched to another method called or "Open Authentication."
BACKGROUND: