This corner of GitHub collects providers for OpenSSL 3.0 and beyond. Some of the providers have repositories here, other are simply linked to below
BLAKE3 provider (blake3-prov) by Jordan M.
Open Quantum Safe provider (oqs-provider) by Open Quantum Safe. This is their liboqs integration in earlier OpenSSL versions, taking the form of a provider for OpenSSL 3.
TPM 2.0 provider (tpm2-openssl) by Petr Gotthard and the tpm2-software community.
MD5 provider by Guodong Xu from Linaro.org. This provider supports an MD5 algorithm implementation. It is based on the multi-threaded version of ISA-L_crypto which allows to harness multiple CPU cores to further increase the bandwidth. The original ISA-L_cypto provides a basic multi-buffer MD5 implementation.
(Windows only) CNG provider by @Lipovlan
Quantis Provider by @cchinchole
The more the merrier. If you know of a provider that isn't presented here, please raise an issue or submit a PR to update this file.