The professional JSON editor with OSCAL integration
More than just an editor
mjEdit is the first and currently the only open-source GUI application that serves as a full-fledged, specialised GUI authoring environment for editing OSCAL JSON files. mjEdit is a professional, fully integrated work environment for daily work with information security management systems (ISMS), designed for use in multi-compliance governance, risk & compliance contexts.
For ISMS practitioners that means: finally a tool that not only displays complex JSON structures transparently, but also makes daily documentation work easier with dynamic forms (qFORM).
Consultants benefit from the multi-tab interface that lets them write policies in Markdown, review compliance documents and work directly in the PDF viewer with annotations or redactions – all at once.
Auditors get a central platform where they can analyse JSON data, supporting documentation and web content side by side in the integrated browser – without media breaks and without switching tools.
Core features at a glance
JSON Editor
Syntax highlighting, real-time validation, auto-repair, regex search, code folding – even for files larger than 1 MB.
qFORM forms
JSON arrays automatically rendered as editable forms with text fields, checkboxes, dropdowns and Python QC scripts.
Markdown editor
Split view, GitHub Flavored Markdown, extended task system with priorities, assignment and PDF/HTML export.
PDF viewer
Annotations (highlighter, notes, freehand), secure text redaction and zoom up to 400 %.
Browser tab
Chromium-based web browser with bookmarks, tabs and lazy loading – right inside the application.
Plugin system
Extensible via hook-based plugins with tab registration and menu integration.
OSCAL compliance – the unique selling point
- All 8 OSCAL document types (v1.2.1) fully supported – from catalog to mapping collection.
- AI integration with 88 MCP tools for AI-driven automation with Claude, Cursor, VS Code Copilot and AnythingLLM.
- Pydantic-based validation – schema-compliant documents from the moment they are created.
- BSI IT-Grundschutz and NIST SP 800-53 preinstalled.
- Network discovery – IP addresses, hostnames and MAC addresses imported into the SSP inventory automatically.