15. A non-transitory computer readable storage medium having code or instructions, which code or instructions when executed on a computer cause(s) a process for Cascading Style Sheet (CSS) selector matching that includes: receiving content including markup language text and text which includes at least one CSS selector; parsing the markup language into a Document Object Model (DOM) tree; parsing the text which includes at least one CSS selector into a data structure representing the at least one CSS selector; generating machine code by compiling the data structure based on the parsing of the text which includes at least one CSS selector; and executing the machine code to perform the CSS selector matching, wherein the executing of the machine code comprises: for each DOM node from said DOM tree, invoking the machine code for the at least one CSS selector to determine whether each of the at least one CSS selector matches the DOM node, and for each of the at least one CSS selector determined to match the DOM node, apply a corresponding CSS property to the DOM node.
15. A non-transitory computer readable storage medium having code or instructions, which code or instructions when executed on a computer cause(s) a process for Cascading Style Sheet (CSS) selector matching that includes: receiving content including markup language text and text which includes at least one CSS selector; parsing the markup language into a Document Object Model (DOM) tree; parsing the text which includes at least one CSS selector into a data structure representing the at least one CSS selector; generating machine code by compiling the data structure based on the parsing of the text which includes at least one CSS selector; and executing the machine code to perform the CSS selector matching, wherein the executing of the machine code comprises: for each DOM node from said DOM tree, invoking the machine code for the at least one CSS selector to determine whether each of the at least one CSS selector matches the DOM node, and for each of the at least one CSS selector determined to match the DOM node, apply a corresponding CSS property to the DOM node. 17. A non-transitory computer readable storage medium according to claim 15 , wherein the machine code into which the data structure is compiled is a set of instructions directly executable by a computer processor, the CSS selector matching is performed by performing the following for each DOM node from said DOM tree: invoking the computer processor to execute the set of instructions to determine whether each of the at least one CSS selector matches the DOM node, and for each of the at least one CSS selector determined to match the DOM node, applying the corresponding CSS property to the DOM node.