Contributor Architecture

Forma keeps public UI behavior runtime-neutral while producing separate MonoGame and FNA binaries. The runtime packages share the Forma namespace and API surface but are not binary substitutes.

Ownership Boundaries

Area	Primary paths	Focused validation
Core controls, layout, input, themes	src/Forma, tests/Forma.Tests	make test-unit, make parity
Dynamic text and Unicode	src/Forma.DynamicText, tools/Forma.UnicodeGenerator	make test-unit, make unicode-verify
Media	src/Forma.Media, video fixtures	make video-smoke, make parity
XAML compiler/build/hot reload	src/Forma.Xaml.*, tests/Forma.Xaml.*	make test-xaml, make format-xaml-check
SVG API and Skia backend	src/Forma.Svg, SVG consumer tests	make svg-selection, make svg-packages
ThorVG backend/native ABI	src/Forma.Svg.ThorVG, native, external/ThorVG	make thorvg-render, make thorvg-nativeaot
Catalog and visual stories	samples/Forma.Catalog*, render tests	make smoke, make render-parity
End-to-end XAML sample	samples/Forma.Xaml.Game*	make test-xaml
Packages and release	project pack metadata, scripts/release-packages.json	bash scripts/pack-release-packages.sh
Documentation and API reference	docs, XML comments, Docfx config	make docs-check
Licenses and provenance	legal files, package payloads, asset manifests	make compliance

Runtime Peer Rule

Shared projects receive FormaRuntime=MonoGame or FormaRuntime=FNA and select exactly one framework reference. Runtime adapters live behind narrow compile-time boundaries. A change to public shared API must produce the same documented signatures in both peers; scripts/check-runtime-parity.sh is the authority.

Data and Resource Ownership

UIContext owns UI traversal and device-bound caches; controls own their retained child structure; applications own resources they pass unless an API explicitly transfers ownership. Build-time XAML injects production loaders into application assemblies. Debug hot reload is a separate package and must not leak into release output. Native backends must fail explicitly when ABI or RID requirements are unmet and may not silently select another renderer.

Generated Surfaces

Theme icons, Unicode data, packages, API YAML, screenshots, metrics, and baselines each have a named generator or source manifest. Change the owner first and run its verification command. Files under Artifacts/, docs/api/, and docs/_generated/ are outputs and are not reviewed as source.

Review Expectations

Cross-boundary changes need the focused checks for every affected owner. Public API changes also need parity and documentation. Rendering changes need visual evidence from both peers or an explicit reason a peer cannot execute on the current host. Native/dependency changes need provenance, redistribution review, clean consumers, and supported-RID evidence.