mceliece.org pages:

• classic.mceliece.org: the Classic McEliece home page, including the Classic McEliece specification, Sage version of the Classic McEliece specification, guide for implementors, documentation for NIST, documentation for ISO, guide for security reviewers
• isd.mceliece.org: information-set decoding, the state-of-the-art attack strategy against the McEliece cryptosystem
• lib.mceliece.org: the libmceliece software library for Classic McEliece

Further resources:

• bench.cr.yp.to: benchmarks of software for many cryptosystems including Classic McEliece
• Botan software library (C++): many cryptosystems including McEliece (but not compatible with Classic McEliece yet)
• Bouncy Castle software library (Java, C#): many cryptosystems including Classic McEliece
• BSI recommendations: two cryptosystems, including Classic McEliece (mceliece460896 and larger), are "cryptographically suitable for long-term confidentiality protection" (2020); the "most conservative choices from the BSI's point of view" (2021); "cryptographically suitable to protect confidential information on a long-term basis" (2023)
• classic-mceliece-rust software library: pure Rust implementation of Classic McEliece
• libmcleece: file-encryption software using Classic McEliece
• liboqs software library: various cryptosystems including Classic McEliece
• mceliece-arm-m4: speed-optimized Classic McEliece software for ARM Cortex-M4
• McEliece attack challenges (started in 2019, ongoing)
• McOutsourcing: space-optimized Classic McEliece software for ARM Cortex-M4
• McTiny: fast Classic McEliece key erasure for tiny network servers
• Mullvad VPN software: 2022 announcement of Classic McEliece experiment on some servers, 2022 announcement of Classic McEliece experiment on all servers, 2023 announcement of stable support for Classic McEliece
• ncsc.nl recommendation (2022) of three cryptosystems, including Classic McEliece
• node-mceliece-nist software library: Node.js bindings for Classic McEliece
• pqc-classic-mceliece: FPGA implementation of Classic McEliece
• PQClean repository: various cryptosystems including Classic McEliece
• PQ-WireGuard VPN software (2020): uses Classic McEliece (mceliece460896) for static keys
• Rosenpass VPN software (2023): uses Classic McEliece (mceliece460896) for static keys