Doxygen vs Theneo

Doxygen is a free documentation generator that turns source-code comments into reference material, parsing items such as classes, functions and variables. It supports C/C++, Lex, Java, Python, VHDL, PHP IDL, C#, Fortran, Objective-C 2.0 and some D sources. Output can be generated as HTML, PDF through LaTeX, Word through RTF or structured XML for external tools. Graphviz’s dot tool can add include-dependency, collaboration, call, directory-structure and class-hierarchy diagrams. Doxywizard provides a graphical interface for editing settings and running the generator on Windows, Linux and macOS; Doxygen also works on many Unix flavors. It supports HTML Help, docsets, Qt-Help and Eclipse Help, with more than 100 configurable options. The tool runs without registration and does not collect personal or usage data. It is self-hosted and licensed under the GNU General Public License, without express or implied warranty. Help is listed through Stack Overflow and the doxygen users mailing list; commercial feature and bug-fix support has limited capacity.

Theneo is a developer portal for publishing API references, guides, changelogs, and customer-specific private portals. It creates interactive API documentation from OpenAPI files, Postman collections, or Git connections, with code samples, live testing, and CI/CD sync. Supported formats include REST, AsyncAPI, SOAP, GraphQL, and gRPC. Teams can co-edit, comment, review changes, track versions, and roll back. AI tools include documentation generation, Ask AI answers, release summaries, MCP, and llms.txt support. Private portals can control API visibility by customer and include SSO options and custom branding. Integrations include GitHub and Bitbucket sync, a VS Code extension, Postman sync, CLI, SDK, and API access. Theneo lists SOC 2 Type II, ISO 27001, and ISO 9001 certifications and GDPR compliance; it describes AES-256 encryption at rest, TLS 1.2 or later in transit, and seven-day point-in-time backups. A free plan is available; Business starts at $120/month billed annually. Enterprise includes self-hosting on AWS, Azure, Google Cloud, or on-premises Kubernetes.