WP4BD - WordPress Theme Compatibility Layer for Backdrop CMS

Bring classic WordPress themes to Backdrop CMS without modification.

What is this?

WP4BD (WordPress for Backdrop) is a backward compatibility layer that allows classic WordPress themes (pre-Block Editor era) to run on Backdrop CMS 1.30. It intercepts WordPress function calls and template suggestions, mapping them to Backdrop's architecture.

Why?

• Effortless migration from WordPress to Backdrop
• Preserve theme investments without rewriting code
• Reduce transition costs dramatically
• Extend the life of existing theme assets

Proof of Concept Target

The initial PoC aims to successfully run the WordPress Twenty Seventeen theme (WordPress 4.9 era) on Backdrop CMS 1.30 without any theme modifications.

Project Components

1. WP-TCL Module - The compatibility layer that implements WordPress function stubs and the Loop logic
2. Bridge Theme - A Backdrop theme that wraps and loads WordPress theme files
3. Twenty Seventeen - The target WordPress theme for initial testing

Scope

Included:

• Classic Editor era themes (WordPress 4.9 and earlier)
• Core template tags and Loop functionality
• Template redirection mechanism
• Asset loading and path management

Excluded:

• Block Editor (Gutenberg) themes
• Complex WordPress plugin APIs
• Full WordPress module compatibility

Status

🚧 In Development - This is an active proof of concept project.

Documentation

For detailed implementation plans, phases, and technical specifications, see:

• Project Plan: WordPress Theme Compatibility Layer.md

Version Context

• Target WordPress Version: 4.9 (last major pre-Gutenberg release)
• Target Backdrop Version: 1.30
• Theme Target: Twenty Seventeen

License

[To be determined]