Aspose.Page for JavaScript via C++ is a JavaScript API designed for working with Page Description Language (PDL) formats, specifically XPS, PostScript (PS), and EPS. It facilitates creation, modification, and conversion of documents without requiring external dependencies, enabling developers to manipulate pages and graphical elements, define vector graphics, group shapes, apply color spaces, and adjust document metadata. Additionally, it supports merging and exporting PDL files into PDF and common raster image formats like BMP, JPEG, PNG, GIF, TIFF, providing a complete, on-premise solution for PDL handling in JavaScript environments.