DDL Parser

NonStop / Base24 / ISO 8583 — multi-message analysis with field tracking.

A single-page tool for reading HPE NonStop DDL definitions and parsing captured messages against them: message-format detection, parse specs, field maps, byte coverage and per-field overrides.

• Live: https://ddl-parser.gu2.dev
• Mirror: https://gatunox.github.io/ddl-parser

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License

Copyright © 2026 Gatunox. All rights reserved.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License, version 3 or (at your option) any later version, as published by the Free Software Foundation.

The full text is in LICENSE. In plain terms:

• You may use it, study it, modify it and share it.
• You must keep the copyright notice and state what you changed.
• You must release any version you distribute or host for others under the AGPL too, with its complete source.
• There is no warranty. See sections 15 and 16 of the license.

That third point is the one people miss. This is a web application, and the AGPL — unlike the ordinary GPL — treats running it on a server for other people the same as handing them a copy. Put a modified version behind a URL and you owe its users the source.

Commercial licensing

The AGPL is deliberately strict, and it does not suit everyone. If you want to

• build on this in a closed-source product, or
• run a modified version as a service without publishing your changes, or
• ship it under terms that AGPL section 13 makes impossible for you,

then you need a separate commercial license, which is available. As the sole copyright holder I can grant terms the AGPL does not.

Contact: [email protected]

Using this software commercially is fine under the AGPL — selling it, offering it as a service, using it at work. What is not fine is doing any of that while keeping your source closed. The commercial license exists for exactly that case.

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Build

source.html is the source of truth. index.html is generated from it and is the file that gets served.

npm run build      # source.html -> index.html (bundles CodeMirror, obfuscates)

The obfuscation in the build is a packaging step, not a licensing one. It does not restrict any right the AGPL grants you: the readable source is in this repository, which is how the license requires it.