FreeType 2.15 Released With Apple HVF Driver, ISO Open Font Format Edition 5

FreeType 2.15 is now available for this widely-used font rendering library used across many different operating systems and software applications. The first major change of FreeType 2.15 is support for ISO Open Font Format Edition 5, which debuted this summer. The updated Open Font Format allows for a new "VARC" table allowing for up to 90% size reduction of CJK Variation fonts, support for more than 65,536 glpys in OpenType fonts, and a new "GLYF" table for outlines with mixed cubic and conic segments. While bringing some nice improvements, this ISO Open Font Format Edition 5 work will upset some due to AI/LLMs involved: "Support for the ISO Open Font Format, Edition 5 (released in July 2026) has been contributed by Behdad Esfahbod, using various LLMs for deriving basic code from HarfBuzz and other implementations, followed by manual fine-tuning, mainly for greater speed." FreeType 2.15 also adds an experiment HVF driver that was contributed by Apple and currently only working on macOS. The HVF driver is for Apple's Hierarchical Variable Font found in newer versions of iOS and macOS for organizing complex glyphs into a nested tree structure. Also significant with FreeType 2.15 is its anti-aliased rasterizer using dynamic heap memory for large glyphs that can improve performance at sizes over 40 ppem. Rounding out the work is TrueType v40's interpreter saw several ClearType rendering improvements. FreeType 2.15 can be downloaded from the project's FreeDesktop.org GitLab.