Opening and Saving

Formats

.designspace	Opens every master it names. This is the normal way to work on a family.
.ufo	Opens as a single master.
A directory	Opens the sources it holds.
.glyphs, .glyphspackage	Converted to UFO and designspace files in a sibling directory, then opened. See below.
.ttf, .otf	A compiled font opens as an editable UFO in memory. See below.

Use File → Open, or start the editor with a path.

Opening a .glyphs file or a .glyphspackage converts it to UFO plus designspace files in a sibling directory and opens those. The original is left alone. Both forms hold the same data, so both convert the same way.

From then on you are working on the converted files: saving writes them, and exporting compiles them. Runebender is not a Glyphs editor that happens to read UFO. It is a UFO editor that can take a Glyphs file as a starting point.

A .ttf or .otf opens as an editable UFO built in memory from the binary. It is a way to look inside a font, take a shape out of one, or start from something that only exists compiled.

Saving writes that UFO next to the binary. It never writes over the binary, and exporting compiles from the UFO rather than touching the original file.

Cmd+N creates an untitled UFO with Google Fonts metrics and the Latin Core glyph set as empty encoded glyphs, then asks where to save it.

Starting from a real glyph set rather than an empty file means the grid, the language coverage rows, and the search all do something from the first minute.

File menu

Save	Cmd+S. Writes every changed master back to disk.
Save As…	Cmd+Shift+S. Choose a new location.
Export…	Cmd+E. Builds a font file. See Exporting.

The header shows the path of the open font and the time of the last save, so you can tell whether what is on screen is on disk.

Runebender watches the files it has open. Edit a UFO with another tool, run a script over it, or check out a different branch, and the editor reloads.

That makes it reasonable to keep the editor open while working on the same font from a terminal.