hashtray is an OSINT (Open Source Intelligence) tool designed to find a Gravatar account associated with an email address and to locate an email address using a Gravatar account username or hash.

Highly portable C system library: threads and synchronization primitives, sockets (TCP, UDP, SCTP), IPv4 and IPv6, IPC, hash functions (MD5, SHA-1, SHA-2, SHA-3, GOST ...