// the find
litespeedtech/lsquic
LiteSpeed QUIC and HTTP/3 Library
LSQUIC is the QUIC and HTTP/3 implementation that LiteSpeed uses in its own web server and load balancer, released as a C library with example client and server programs. It suits teams embedding QUIC into their own server or client code, and it is a poor fit for anyone who wants a ready-to-run HTTP/3 server.
- Standards coverage is wide for a C library. RFC 9000, 9001, 9002, 9114, and 9204 are listed, along with the datagram extension (RFC 9221), QUIC version 2 (RFC 9369), and extensible prioritization (RFC 9218).
- The code runs in production. The README says most of it ships in LiteSpeed Web Server, LiteSpeed ADC, and OpenLiteSpeed, which is a stronger signal than a library that only passes its own tests.
- The tests directory has per-component unit tests for frame parsing, CUBIC, and the bandwidth sampler, and `make test` runs them. That is more than most QUIC libraries of this size publish.
- CI covers Linux, macOS, Windows, and FreeBSD, and the README includes a Dockerfile for building the library and examples.
- BoringSSL is not packaged. You clone it, check out a pinned tag (0.20250807.0 in the README), and build it before LSQUIC will compile. That is real onboarding friction, and the pin will drift from whatever your system or package manager provides.
- The README says the examples are where API usage lives, and the example programs use libevent for the event loop. Expect to read bin/ before the API reference makes sense, and expect to write your own loop integration.
- Compliance is described as 'mostly' for the listed RFCs, and the README does not say which parts are missing. Check the specific behaviour you need against the code before you commit to it.
- Most of the code exists to serve LiteSpeed's own products. Priorities and fixes will follow their needs, and outside contributors should expect that. The README lists Windows support as x86_64 only.