UFO sources

Format notes.

Runebender is organized around source fonts that can be inspected, versioned, and moved between tools. These notes map the format surface without pretending the whole compatibility story is settled.

StatusFormat orientation
AudienceFont developers and tool authors
SourceRunebender Xilem hyperbezier spec
StabilityVerify against source before relying on details

UFO

UFO is the current source workflow named in the Runebender Xilem README. Public docs should keep read/write expectations clear and conservative while the editor is alpha.

Hyperbezier

Runebender Xilem supports on-curve hyperbezier paths, with off-curve control points computed by a spline solver. Hyperbezier contours are marked in GLIF with identifier="hyperbezier".

The canonical spec lives in the source repo at docs/hyperbezier-ufo-extension.md. This site should summarize it, not fork it.

Compatibility

Questions to answer before public docs
ReadDocument which UFO/GLIF structures are accepted as each editor path matures.
WriteKeep save behavior conservative and version-control friendly.
FallbackNon-supporting editors may ignore the hyperbezier identifier or treat points as ordinary curve/line points.
ExportKeep release docs clear about what exists now versus future work.