phpDocumentor vs Scalar

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.

Scalar is a set of API products for documentation, SDK generation, API registries, API requests, and MCP server use. Scalar Docs combines product guides and interactive API references generated from OpenAPI documents in a developer portal. Teams can write in Markdown or MDX, use GitHub content, preview pull requests, and publish through a CLI or after a merge. The SDK Generator builds idiomatic, type-safe client libraries from OpenAPI documents and can publish them through repository pull requests. Registry stores and versions OpenAPI and AsyncAPI documents, JSON Schema, and Spectral rules with Git integration. The open-source API Client works offline for sending requests, organizing collections, and testing APIs from OpenAPI documents. Scalar supports hosted and self-hosted deployment. Its Free plan is free and includes up to three APIs, one SDK with up to 25 endpoints, one editor seat, and 50 Agent Scalar credits. Pro is $150 a month; Business is $600 a month. Scalar states that it has received a SOC 2 Type 1 report and maintains GDPR-compliant privacy practices.