An XProc script is edited as an XML document that is validated against a RELAX NG schema. If the script has an associated transformation scenario, then the XProc engine from the scenario is invoked as validating engine. The default engine for XProc scenarios is the Calabash engine which comes with Oxygen XML Developer plugin version 14.2.
The content completion inside the element input/inline from the XProc namespace http://www.w3.org/ns/xproc offers elements from the following schemas depending on the port attribute of input and the parent of input. When invoking the content completion inside the XProc element inline, depending on the attribute port of its parent input element and the parent of element input, elements from different schemas are offered inside the proposals list.
The XProc editor renders with dedicated coloring schemes the XPath expressions. You can customize the coloring schemes in thepreferences page.
XProc Content Completion