XMP:

Stands for "Extensible Metadata Platform." XMP is a universalmetadata format developed by Adobe Systems and standardized by the International Organization for Standardization (ISO). It provides a standard format for sharing metadata between multiple applications.
XHTML:
Stands for "Extensible Hypertext Markup Language." Yes, apparently "Extensible" starts with an "X." XHTML is a spinoff of the hypertext markup language (HTML) used for creating Web pages. It is based on the HTML 4.0 syntax, but has been modified to follow the guidelines of XML, the Extensible Markup Language. Therefore, XHTML 1.0 is sometimes referred to as HTML 5.0.
Because XHTML is "extensible," Web developers can create their own objects and tags for each Web page they build. This gives the developers more control over the appearance and organization of their Web pages. The only requirement is that the custom tags and attributes are defined in a document type definition (DTD), that is referenced by the XHTML page.

XML:
Stands for "Extensible Markup Language." (Yes, technically it should be EML). XML is used to define documents with a standard format that can be read by any XML-compatible application. The language can be used with HTML pages, but XML itself is not a markup language. Instead, it is a "metalanguage" that can be used to create markup languages for specific applications. For example, it can describe items that may be accessed when a Web page loads. Basically, XML allows you to create a database of information without having an actual database. While it is commonly used in Web applications, many other programs can use XML documents as well.


XSLT:Stands for "Extensible Style Sheet Language Transformation." While XML is supposed to be a standardized language, not allow XML documents use the same type of formatting. Therefore, the documents sometimes need to be "transformed," or modified so that another script or program will be able to read them. XSLT make this transition possible. An XSLT style sheet provides a template with rules that XML documents must conform to. It receives an XML document as input and outputs a file that is recognizable by the intended program. For example, an XSLT may take a XML document that contains the technical specifications of a computer and turn it into an HTML page that can be displayed in a Web browser. Another XSLT may turn a XML document containing new stories and turn it into a printer-friendly text document. XSLTs can be used to transform XML documents into a modified XML file or a completely separate format, such as the HTML and text examples above. In fact, by using XSLT style sheets, it is possible to output the same XML document on the Web, in a database program, in an e-mail message, or in a printed document. Also, because XML uses standard formatting based on tags, a single XSLT can be effective on a large range of XML-formatted files.
X86- x86 is the generic name for Intel
processors
released after the original 8086 processor. These include the 286, 386, 486, and 586 processors. As you can see, the "x" in x86 stands for a range of possible numbers. Technically, x86 is short for 80x86 since the full names of the processors are actually 80286, 80386, 80486, and 80586. The "80" is typically truncated to avoid redundancy.