fontTools

FontTools is an open-source collection of Python libraries and command-line tools for manipulating font files, particularly TrueType and OpenType fonts. It provides facilities to parse, inspect, modify, and generate font data, including outlines, tables, kerning, and features. The project supports both static and variable fonts and can convert fonts to and from a human-readable XML representation for inspection and editing.

The core library, fontTools.ttLib, offers a Python API to read and write font files, while additional modules handle tasks such as subsetting (fontTools.subset), variable font support (fontTools.varLib), feature code handling (fontTools.feaLib), and outline drawing (fontTools.pens). The ttx tool enables round-tripping fonts through an XML format for easier analysis and modification.

FontTools is used in font development workflows, typography pipelines, and tooling that requires programmatic access to font data. It is widely adopted in the open-source font community and serves as a foundation for other projects and utilities that manipulate font information.

Licensing and availability: The project is released as open-source software and is maintained publicly on repository hosting platforms. Its flexible API and comprehensive toolkit make it a common resource for developers working with font files across different platforms and formats.