# ALTO PHP

> Modern packages for PHP 8.3+ with typed APIs, thorough test suites, focused dependencies, and production-oriented performance.

ALTO PHP provides focused packages for content processing, developer tools, and asset pipelines. Start with the [ALTO PHP website](https://altophp.com/) to explore them. Each package below links to its machine-readable documentation index and names its Composer package.

ALTO PHP is a family of open-source PHP libraries for building content tools,
documentation systems, developer interfaces, and asset pipelines. Its packages
cover document processing, source code, images, fonts, and web standards. Install
the components your application needs; each has its own Composer package and
repository, and complementary packages can be composed into a larger workflow.

The family is created and maintained by [Simon André](https://smnandre.dev/)
([smnandre on GitHub](https://github.com/smnandre)), a PHP and Symfony developer,
Symfony UX core team member, and creator of ALTO, Atelier SVG, PHPColor, and
Playwright PHP. The [ALTO PHP GitHub organization](https://github.com/altophp)
hosts the source repositories, issue trackers, and contributions. Development
can be supported through [GitHub Sponsors](https://github.com/sponsors/smnandre).

The shared foundation is MIT licensing, Composer installation, PSR-4 autoloading
under `Alto\`, typed PHP APIs, and repository checks using PHPUnit, PHPStan, and
PHP CS Fixer. The focus is on explicit behavior, standards-based formats, and
small components with documented contracts. Core libraries work independently
of a web framework; integration packages connect them to tools such as Twig.
Runtime dependencies and PHP extensions vary by package.
Markdown, RST, Image, and Code Highlight have no third-party Composer runtime
dependencies; Image rendering still requires GD or Imagick.

Names follow three related conventions: `alto/<package>` on
[Packagist](https://packagist.org/packages/alto/), `altophp/<repository>` on
GitHub, and a package-specific PSR-4 prefix in PHP. For example,
`alto/markdown` maps to `altophp/markdown` and `Alto\Markdown\`;
`alto/code-highlight` maps to `altophp/code-highlight` and `Alto\Code\Highlight\`.
Use each package's published Composer metadata for its exact requirements and
available releases. Documentation describes the source used to build this site;
check the installed version when adopting an API.

## Markup

- [ALTO Markdown](https://altophp.com/markdown/llms.txt): PHP 8.3+ package `alto/markdown` - Markdown document engine: parse, query, lint, build, render, and safely edit Markdown with minimal diffs.

- [ALTO RST](https://altophp.com/rst/llms.txt): PHP 8.3+ package `alto/rst` - reStructuredText document engine: parse, query, lint, build, render, translate, and safely edit RST with minimal diffs.

- [ALTO Front Matter](https://altophp.com/frontmatter/llms.txt): PHP 8.3+ package `alto/frontmatter` - Fast front matter extraction and strict YAML-subset decoding for PHP.


## Syntax

- [ALTO Code Highlight](https://altophp.com/code-highlight/llms.txt): PHP 8.3+ package `alto/code-highlight` - Semantic syntax highlighting in PHP, with embedded languages and Highlight.js, Prism, and TextMate theme adapters.

- [ALTO Twig Code Highlight](https://altophp.com/twig-code-highlight/llms.txt): PHP 8.3+ package `alto/twig-code-highlight` - Twig extension for Alto Code Highlight.


## Code

- [ALTO Code Slicer](https://altophp.com/code-slicer/llms.txt): PHP 8.3+ package `alto/code-slicer` - Extract source-code slices by line, text, or language structure while preserving original line numbers.

- [ALTO Code Snippet](https://altophp.com/code-snippet/llms.txt): PHP 8.3+ package `alto/code-snippet` - Represent immutable code snippets with source lines, selections, and presentation-neutral annotations.

- [ALTO Code Kit](https://altophp.com/code-kit/llms.txt): PHP 8.3+ package `alto/code-kit` - Compose source slicing and semantic highlighting into immutable annotated code snippets.

- [ALTO Code Diff](https://altophp.com/code-diff/llms.txt): PHP 8.3+ package `alto/code-diff` - Generate, render, and apply code diffs.

- [ALTO Language](https://altophp.com/language/llms.txt): PHP 8.3+ package `alto/language` - Programming language identification: extensions, aliases, markers.

- [ALTO JSON Patch](https://altophp.com/json-patch/llms.txt): PHP 8.3+ package `alto/json-patch` - RFC 6902 JSON Patch: smart diffs, patching, audit and versioning.


## Assets

- [ALTO Image](https://altophp.com/image/llms.txt): PHP 8.3+ package `alto/image` - Lazy image resizing, cropping and encoding with predictable geometry and efficient multi-output rendering.

- [ALTO Favicon](https://altophp.com/favicon/llms.txt): PHP 8.3+ package `alto/favicon` - Generate a modern favicon set from a single SVG or PNG file.

- [ALTO Importmap](https://altophp.com/importmap/llms.txt): PHP 8.3+ package `alto/importmap` - Manage, render, and resolve Import Maps.

- [ALTO Font](https://altophp.com/font/llms.txt): PHP 8.3+ package `alto/font` - Read, inspect, convert, and subset OpenType, TrueType, WOFF, and WOFF2 fonts in PHP.


## Design

- [ALTO Bezier](https://altophp.com/bezier/llms.txt): PHP 8.3+ package `alto/bezier` - Precision toolkit for Bezier curves: evaluate, split, and measure.

- [ALTO Scale](https://altophp.com/scale/llms.txt): PHP 8.3+ package `alto/scale` - Compute and manipulate modular scales: typography, rhythm, grids.

- [ALTO Tree](https://altophp.com/tree/llms.txt): PHP 8.3+ package `alto/tree` - Build, parse, traverse, and print tree structures.