There are 2 repositories under proof-automation topic.
Lean 3's obsolete mathematical components library: please use mathlib4
Proof Updater Mechanically Passing Knowledge Into New Proofs, Assisting The Coq Hacker
Proof automation – for Agda, in Agda.
A web-based graphical proof assistant for LK and Hoare logic.
Ring, field, lra, nra, and psatz tactics for Mathematical Components
a linear logic prover based on Naoyuki Tamura's llprover that works under SWI Prolog
multi-logic proof generator
Library for formalizing cryptography proofs in Lean 3 (Deprecated)
The Open Deduction Proof Editor allows proof theorists (or anyone) to deconstruction proofs step by step. It currently supports deep inference formalisms, namely Open Deduction and naturally the Calculus of Structures. The front end of the application is written in Java, while the back end is written in Maude. There is also an implementation of proof search both with and without proof variables.