12. A system for performing error checking on a structured document, comprising: one or more processors that are capable of performing multi-threaded executions and are implemented at least partially by hardware; and a storage medium that stores computer program logic that is executable by the one or more processors, the computer program logic comprising: a parser configured to be executed by a first thread of execution on at least one of the one or more processors, the parser being further configured to: identify one or more new elements in the document, assign an identifier (ID) to each new element, and store a copy of each new element in a first queue, the copy of each new element including the ID associated with the new element and at least one of text and structural information associated with the new element; and an error checker configured to be executed by a second thread of execution on the at least one of the one or more processors, the error checker being further configured to: retrieve each copy of each new element from the first queue, apply error checking to each retrieved copy of each new element to detect errors associated therewith, and in response to detecting an error associated with a retrieved copy of a respective new element, generate an error checking result comprising at least the ID associated with the retrieved copy of the respective new element.
12. A system for performing error checking on a structured document, comprising: one or more processors that are capable of performing multi-threaded executions and are implemented at least partially by hardware; and a storage medium that stores computer program logic that is executable by the one or more processors, the computer program logic comprising: a parser configured to be executed by a first thread of execution on at least one of the one or more processors, the parser being further configured to: identify one or more new elements in the document, assign an identifier (ID) to each new element, and store a copy of each new element in a first queue, the copy of each new element including the ID associated with the new element and at least one of text and structural information associated with the new element; and an error checker configured to be executed by a second thread of execution on the at least one of the one or more processors, the error checker being further configured to: retrieve each copy of each new element from the first queue, apply error checking to each retrieved copy of each new element to detect errors associated therewith, and in response to detecting an error associated with a retrieved copy of a respective new element, generate an error checking result comprising at least the ID associated with the retrieved copy of the respective new element. 17. The system of claim 12 , wherein the error checker is configured to apply error checking to a retrieved copy of a new element responsive to determining that an element currently exists within the document that has an ID that is the same as the ID associated with the retrieved copy of the new element.