1. A system for providing highlight rendering services to a plurality of extensions in an extensible editor, the system comprising: a processor; and computer readable storage media having computer-executable instructions stored thereon that when executed by the processor perform a method comprising: receiving a request from one of the extensions to utilize the highlight rendering services; facilitating the request by presenting a highlight rendering services interface that is accessible by the extension and that provides one or more methods to enable the extensible editor to control which section of an electronic document is highlighted on a screen and to control a style of the highlight, the extensible editor determining a visual aspect of the highlight without altering the electronic document and a highlight rendering services component determining non-visual functional aspects of the highlight; registering the extensions in a sequential order; routing an event related to the highlight rendering services component to at least one of the extensions based at least in part on the sequential order in which the extensions are registered; and communicating with the extension through the highlight rendering services interface to enable the extension to highlight a section of a document through the editor according to particular display attributes defined by the extension.
6. The system of claim 1 , wherein the highlight rendering service interface further comprises a move-segment-to-pointers method to enable the extension to create a highlighted segment between two display pointers in the document.