These are the third party libraries used by MuPDF.

Library | Version | Function | License
--- | --- | --- | ---
Required:
freetype | 2.10.4 with patches | Font scaling and rendering | BSD-style
harfbuzz | 2.7.4 | Text shaping | MIT-style
libjpeg | 9.0d with patches | JPEG decoding | BSD-style
Incompatible fork of lcms2 | 2.9 with patches | Color management | MIT-style
openjpeg | 2.4.0 with patches | JPEG 2000 decoding | BSD-style
zlib | 1.2.11 | Deflate compression | zlib License
gumbo-parser | 0.10.1 | HTML5 parser | Apache 2.0
Optional:
FreeGLUT | 3.0.0 with patches | OpenGL API for UI | MIT-style
curl | 7.66.0 with patches | HTTP data transfer | MIT-style
JPEG-XR reference | 1.32 with patches | JPEG-XR decoding | special
Tesseract | 5.0.0-alpha-20201231 with patches | OCR | Apache 2.0
Leptonica | 1.80.0 with patches | Tesseract dependency | BSD-style

NOTE: jbig2dec and MuJS are included in "thirdparty" but are copyright Artifex Software Inc.