Cesium Native relies on a number of third-party dependencies. These dependencies are automatically resolved and built using vcpkg at compile time.

Dependency	Usage
Async++	Used by CesiumAsync for cross-platform concurrency.
Catch2	Test framework used by CesiumNativeTests.
draco	Required to decode meshes and point clouds compressed with Draco.
earcut	Polygon triangulation library for used by CartographicPolygon.
expected-lite	Implementation of the `std::expected` proposal for returning either an expected value or an error value.
glm	C++ mathematics library powering the high-precision math needed for geospatial software.
meshoptimizer	Required to decode meshes compressed with meshoptimizer.
httplib	Used by CesiumIonClient to interact with the Cesium ion REST API.
Ktx	Required to load KTX GPU compressed textures.
libmorton	Implementation of Morton codes used for implicit tiling.
libjpeg-turbo	Decodes JPEG images.
libwebp	Decodes WebP images.
modp_b64	Decodes and encodes base64.
OpenSSL	Required by s2geometry, and also used to generate unique authorization tokens for authenticating with Cesium ion.
PicoSHA2	Generates SHA256 hashes for use with the Cesium ion REST API.
RapidJSON	For JSON reading and writing.
s2geometry	Spatial indexing library designed for geospatial use and required by some tilesets.
spdlog	Logging.
sqlite3	Used to cache HTTP responses.
stb_image	A simple image loader.
tinyxml2	XML parser for interacting with XML APIs such as those implementing the Web Map Service standard.
uriparser	Used to parse and manipulate URIs.
zlib-ng	An optimized zlib implementation for working with Gzipped data.

The following chart illustrates the connections between the Cesium Native libraries and third-party dependencies: