IRen

IRen (formerly XEP) is the formatting engine at the heart of every RenderX publishing solution. It takes XML input, applies an XSL transformation to produce XSL Formatting Objects, and formats the result into print-ready PDF, PostScript, and AFP. The engine kernel has been refined through more than two decades of production deployment, from single technical manuals to high-volume statement runs.

XEP 4.31 (November 2025) was the final release in the XEP line. IRen is its successor and is fully backward-compatible: existing stylesheets, configuration files, and integrations continue to work unchanged.

Key capabilities

• Conforms to the W3C XSL 1.0 Recommendation and supports a subset of SVG 1.1 for vector graphics
• Core output: PDF (including PDF/X and PDF/A), PostScript level 2 and 3, and RenderX intermediate XML
• Add-on output modules: AFP, PDF Forms, Microsoft XPS, PPML, SVG, and HTML
• Handles raster and vector graphics formats, barcodes, and fine typesetting

Technical details

IRen accepts XML plus XSLT stylesheets or ready-made XSL-FO. The engine is written in Java and runs on Linux, Unix, Microsoft Windows, and macOS — anywhere a Java Virtual Machine is available. Authors can invoke it directly from XML editors such as oXygen, XMetaL, jEdit, or Emacs; server installations drive database reporting, personalized correspondence, and on-demand document generation from application code.

IRen on Windows

For Windows shops, IRen ships with a .NET service layer that wraps the full engine and exposes its rendering functionality to .NET applications and programming interfaces. The package includes a command-line tool, a .NET assistant GUI for interactive XML and XSL conversion, and a hot-folder application: drop files into a watched folder, attach an XSL transformation per folder, and collect formatted output automatically. Same engine, same output quality, Windows-native integration.

Deployment

Run IRen on a desktop, embed it in a server application, or scale it out. For containerized and high-volume environments, IRen InGrid distributes formatting across a grid of engines with a REST API, a Docker Hub image, and Kubernetes deployment support.

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