# pTeX > Extension of TeX for Japanese typeset **Wikidata**: [Q11240062](https://www.wikidata.org/wiki/Q11240062) **Source**: https://4ort.xyz/entity/ptex ## Summary pTeX is an extension of the TeX typesetting system specifically designed to support Japanese typesetting. It is classified as free software and is licensed under the 3-clause BSD License. The software is cross-platform and serves as a foundational tool for Japanese document preparation within the TeX ecosystem. ## Key Facts - **Primary Function:** Extension of TeX for Japanese typesetting. - **Base System:** Built upon TeX (a typesetting system originated in 1978). - **License:** Distributed under the 3-clause BSD License. - **Aliases:** Also known as PLaTeX and PTeX. - **Operating System:** Cross-platform (capable of operating on multiple computing platforms). - **Software Class:** Typesetting software and free software. - **Official Website:** https://texjp.org/ - **Package Availability:** Available in Debian and Ubuntu repositories via the `texlive-lang-japanese` package. - **Source Repositories:** Maintained on GitHub at `texjporg/ptex-base`, `texjporg/platex`, and `texjporg/ptex-fonts`. ## FAQs ### Q: What is pTeX used for? A: pTeX is used for typesetting documents in Japanese. It extends the standard TeX system to handle the specific requirements of Japanese text layout. ### Q: Is pTeX free to use? A: Yes, pTeX is classified as free software. It is distributed under the 3-clause BSD License, allowing users to run, study, and modify the software. ### Q: On which operating systems can pTeX run? A: pTeX is cross-platform software, meaning it is capable of being implemented and operating on multiple computing platforms. ### Q: How is pTeX installed on Ubuntu or Debian systems? A: pTeX is included in the `texlive-lang-japanese` package for both Debian stable and Ubuntu distributions. ## Why It Matters pTeX plays a critical role in the digital publishing and academic landscape by bridging the gap between Donald Knuth’s original TeX system and the complex requirements of the Japanese writing system. Standard TeX was designed primarily for English and mathematical typesetting; without pTeX, producing high-quality, professional documents in Japanese using TeX would be significantly more difficult. By providing a specialized engine for Japanese typeset, pTeX enables authors, researchers, and publishers in Japan to leverage the precise typographical capabilities of TeX. Furthermore, the project's status as free software under a permissive BSD license ensures that these tools remain accessible to the community. Its integration into major Linux distributions (via `texlive-lang-japanese`) highlights its status as a standard, reliable component of the modern TeX ecosystem, maintained actively by the TeX Japanese Organization (texjporg) through open-source repositories. ## Notable For - **Japanese Localization:** Being a dedicated extension of TeX specifically optimized for Japanese typesetting. - **Open Source:** Licensed under the 3-clause BSD License, facilitating open contribution and distribution. - **Cross-Platform Compatibility:** Functioning across various operating systems rather than being restricted to a single environment. - **Ecosystem Integration:** Serving as the core engine referenced by the `texlive-lang-japanese` package in major Linux distributions. - **Active Maintenance:** Having dedicated source code repositories managed by the texjporg organization on GitHub. ## Body ### Origins and Classification pTeX is identified as an instance of typesetting software and free software. It functions as a direct extension of TeX, the typesetting system created by Donald Knuth (inception 1978). While TeX provides the underlying logic for document formatting, pTeX adds the necessary logic to process and render Japanese characters correctly. ### Technical Specifications The software is designed to be cross-platform, ensuring usability on diverse computing environments. The project is associated with the Google Knowledge Graph ID `/g/122mkvvv` and has a dedicated Stack Exchange tag (`https://tex.stackexchange.com/tags/ptex`) for community support. ### Licensing and Copyright pTeX is copyrighted software distributed under the **3-clause BSD License**. This license permits users to freely use, study, change, and distribute the software and its modified versions, aligning with the definition of free software. ### Distribution and Installation For users on Linux systems, pTeX is distributed through the `texlive-lang-japanese` package. This package is the standard for both **Debian stable** and **Ubuntu** environments. The Repology project name for tracking this software is `texlive:ptex`. ### Development and Resources The project is maintained by the TeX Japanese Organization. The official website is hosted at **https://texjp.org/**. The source code is publicly accessible and managed across three primary GitHub repositories: 1. **ptex-base:** https://github.com/texjporg/ptex-base 2. **platex:** https://github.com/texjporg/platex 3. **ptex-fonts:** https://github.com/texjporg/ptex-fonts ## References 1. [Source](https://github.com/texjporg/ptex-base/blob/2017-08-27/LICENSE)