Well it's not a programming language at all actually. XML stand for eXtensible Markup Language.

w3c.org: {
Extensible Markup Language (XML) is a simple, very flexible text format derived from SGML (ISO 8879). Originally designed to meet the challenges of large-scale electronic publishing, XML is also playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere.
}

it can get pretty complicated, but the basics are simple enough and a decent way to bypass alot of cross-tech crap that you get when you can't stand using Microsoft's suite of crap because you can't stand reading their deplorable documentation.
<DICTIONARY>
...
<ENTRY word="XML" isNoun="YES">
<DEFINITION>
see above
</DEFINITION>
</ENTRY>
...
</DICTIONARY>
by roke March 14, 2004
The gynecologist likes to XML.
I could tell from the semi bulging from his pants.
by Assweepay August 13, 2005
Recent variant of HTML;Hypertext Markup Language.

XML is useful in short documentations and other odd works that don't matter.
by larstait October 16, 2003
An XML Molester is any programmer who believes that he must learn the structure of Visual Studio XML config files; files that are automatically generated and automatically managed by Visual Studio.NET. XML Molesters compulsively memorize the tag structure of SOAP messages, and practice writing XML data sets (XSD files) by hand using notepad. They often enjoy embarrassing seasoned pros over their apparent lack of XML knowledge and skill.

XML Molestation is considered a profound psycho-sexual pathology by most healthy, wealthy, and wise Visual Studio programmers. Like a Peeping Tom, XML Molesters feel a desperate and uncontrollable need to peek under Visual Studio’s panties to get a gander at what the lady really looks like on the inside. What they don’t understand is that such crass anatomical knowledge of Visual Studio’s private parts is not necessary for a productive business relationship with the lady. Indeed, it is usually counter productive. XML Molestation can lead to major project corruption, as Visual Studio.NET can become quite angry when you poke her in the nether regions, and chew your project up.
Ron of IT Professionals Inc. is a real XML molester. I heard him interviewing a 10 year veteran programmer the other day. He chewed this guy a new one because he couldn't explain XML tag structure of SOAP envelope, and a web.config file.
by Bochambo Lochacopota February 25, 2006