phpDocumentor vs RDoc

phpDocumentor is a free, open-source, self-hosted tool for analyzing PHP source code and DocBlock comments to produce API documentation. It can generate UML diagrams, parse Markdown and reStructuredText, and insert API-documentation sections into reStructuredText material. The site says full-text search works offline and describes CI integration through a GitHub Action or Docker image. Installation options include Docker, Phive, and a PHAR file; standalone installation requires PHP 8.1.2 or newer plus mbstring, while PlantUML is optional. The official Docker image supplies dependencies locally. The project also offers Composer-installable components for parsing, rendering, type resolution, and PHP reflection. It runs on Linux and macOS. Its Docker Hub overview does not actively support direct Composer installation because dependency conflicts may occur. No paid plans are listed; the plan costs nothing.

RDoc is free software for producing Ruby project documentation as HTML pages and command-line reference output. The `rdoc` command generates documentation, while `ri` displays it. It processes Ruby, C, and RBS source files, plus RDoc markup, Markdown, RD, and TomDoc documents. RBS declarations can describe classes, modules, methods, attributes, and constants, and can add comments or type signatures to matching Ruby source documentation. A local preview server watches source files and refreshes the browser after changes. It uses Ruby’s built-in TCPServer and needs no external gems, but provides neither HTTPS nor HTTP/2 and is intended only for local previews. RDoc reports documentation coverage with `rdoc -C`, or includes parameter names with `rdoc -C1`. Generation can be automated through Rake or the RDoc API. Aliki is the default theme; Darkfish is deprecated. Ruby 3.2.0 or newer is required for the current gem.