UFO Converter

UFO (Unified Font Object) is an open, XML-based font source format designed by Tal Leming, Just van Rossum, and Erik van Blokland, with the first version published in 2004. Unlike compiled binary fonts, a UFO is a directory structure containing separate XML files for each glyph (in GLIF format), font metadata (fontinfo.plist), kerning data, groups, and feature definitions. This decomposed architecture was purpose-built for collaborative font development — each glyph exists as its own file, making granular version control with Git or similar systems practical and clean. The format is explicitly application-independent, serving as an interchange layer between different font editors (RoboFont, Glyphs, FontForge, FontLab) rather than locking designers into a single tool. UFO 3, the current major version released in 2012, supports cubic and quadratic outlines, guidelines, anchors, image references, custom data storage, and layered design sources for interpolation. A defining advantage is collaboration-friendliness: teams of designers can work on different glyphs simultaneously and merge changes through standard VCS workflows without conflict. The human-readable XML format provides another benefit — every aspect of the font design can be inspected, diffed, and scripted using standard programming tools. The UFO specification is hosted as an open standard, and an active ecosystem of Python libraries (fontTools, ufoLib2, defcon) provides programmatic access for automated font production pipelines. Major type foundries and open-source font projects increasingly adopt UFO as their canonical source format.