Richie Rich is an HTML document editor that runs within a Web browser. Unlike other in-line HTML editors, this operates straight on the DOM to avoid incongruities between what is visible in the front end and the HTML that is created in the back end. It supports undo, mouse selection, cursor positioning, and creation of headings, paragraphs, lists, links, bold, italic, and underline.
Tartan is a text parsing engine targeted at wiki text. The syntax specification is defined in YAML in the form of regex-based rules. It supports layering and multiple output types. Rules for Markdown to HTML are included, with optional layered extensions for tables. It is implemented in Ruby, but looking to have implementations in other languages.
CDuce is a programming language adapted to writing safe and efficient applications that manipulate XML documents. A type system checks at compile time that applications deal with all the possible inputs and produce only valid outputs. Pattern matching is a powerful operation based on regular expressions to inspect documents. CDuce also features general-purpose features; it is a higher-order functional language, with a type-safe interface with Objective Caml.