The y_crypto library contains a number of PostgreSQL extension functions, primarily written in C. These include random number generation, generating hash digests, and RSA encryption, decryption, signing, and signature verification.
GtkHash is a utility for computing message digests or checksums. Currently supported hash functions include MD5, MD6, SHA1, SHA256, SHA512, RIPEMD, TIGER, and WHIRLPOOL.
A recommendation engine built inside PostgreSQL.
A fast map renderer for Minecraft.