Alternatives to Sandcastle Help File Builder

Scalar

Scalar suits development teams building and documenting APIs from OpenAPI documents, especially those using GitHub workflows.

This tool suits developers who need generated schema documentation for repositories, offline use, GitHub, or TechDocs and MkDocs Material.

Redocly

Redocly suits developers, technical writers, product managers, and executives working on API documentation and governance.

DocFX

DocFX suits teams building technical documentation sites from .NET, REST API and Markdown content.

Sphinx

Sphinx suits developers and documentation teams building structured technical guides, especially those who need cross-references or generated API documentation.

RDoc suits Ruby projects that need generated HTML and command-line API references from source and markup files.

It suits TypeScript projects that need generated HTML or JSON reference documentation, including npm monorepos.

Doxygen

Doxygen suits developers who want to generate reference documentation from source comments across its supported languages.

mdBook suits developers creating documentation, tutorials, or course materials from Markdown.

Natural Docs suits developers and teams that want to generate HTML documentation from code comments or text files.

StepShot suits Mac users creating SOPs, customer support knowledge bases, project delivery documents, or new-hire training.

MkDocs suits people creating project documentation sites from Markdown files who want static HTML output and control over themes and extensions.

phpDocumentor

phpDocumentor suits PHP developers and teams maintaining self-hosted documentation workflows.

Scaladoc suits Scala library authors who want API documentation generated from code comments, as well as library users who need to consult that documentation.

Stoplight Elements

Elements suits developers who need self-hosted, embeddable API reference documentation from OpenAPI files.

unittest

It suits Python developers who need built-in unit-test organization, command-line discovery, assertions, mocks and CI integration across Linux, macOS or Windows.