FAQ

What it is

Is it ready for production work?	No. It is alpha. It writes to your sources in place, so keep them in version control and work on copies.
What does it cost?	Nothing. Apache-2.0 or MIT.
Is this an official Linebender project?	No. It is built on Linebender crates and aims at the Linebender stack, but the site and the editor are maintained independently.
Why are there several front-ends?	One editing core with interchangeable interfaces. GPUI is the current default; the Xilem port exists to compare the two on the same application. See Development.

Formats

What can it open?	UFO, designspace, .glyphs, .glyphspackage, and compiled .ttf or .otf. See Opening and Saving.
Can it write .glyphs?	No. Glyphs files are converted to UFO on the way in, and you work on the converted files.
Will it overwrite my .ttf?	No. A compiled font opens as a UFO in memory, and saving writes that UFO beside the binary.
Does it read FontLab or FontForge sources?	No.
Can another editor open what it saves?	Yes. It writes standard UFO, and uses the glyphsLib keys for Glyphs-compatible data rather than inventing its own. See File Format.

Install and launch

Is there a download?	Not yet. Build it with cargo, or use the browser build. See Install.
Does the browser version upload my font?	No. It runs entirely in the browser. Nothing is sent anywhere.
Why is the browser version limited?	Its platform layer is younger than the native one. The gaps are listed in Troubleshooting.
Windows and Linux?	The code is cross-platform and builds there, but macOS is where it is used daily and where problems get found first.

Common confusions

Why will my glyph not interpolate?	The masters disagree about contour count, point count, point order, or start point. See Concepts and Checking a Font.
What is a hyperbezier?	A curve defined by the points you place, with the handles solved rather than positioned. Convert to cubics before handing the source to a tool that expects them.
Why does my Arabic not join?	Usually glyph names. Shaping engines find joining forms by name. Run Glyph → Check Joining. See Text and Shaping.
Can I script it?	Not from inside the editor. It reloads files changed on disk, so a script and the editor can share a font. See Scripting.
Does it use AI?	It can run a model on your machine, over your sources, with nothing sent anywhere. One job so far: proposing a heavier master from a lighter one. It is experimental and often wrong. See Local Models.

Open an issue on the repository. A useful report says what you did, what happened, and what you expected, and names the file and whether you were in the browser or the native application. If the editor wrote something wrong into a source, the diff from version control is the best evidence there is.