Top SIGNATURE GitHub Repositories & Tools (2026)

The Open Source DocuSign Alternative.

Free on-device iOS/iPadOS application manager/installer, using certificates part of the Apple Developer Program.

pyHanko: sign and stamp PDF files

Cross-platform & feature rich iOS/iPadOS/tvOS sideloading application. Formerly known as PlumeImpactor.

Quantum Resistant Ledger

Stake-based threshold multi-signatures protocol

PDF Rendering and Viewing API in Java

CIDRAM: Classless Inter-Domain Routing Access Manager.

A modern, cross-platform OpenPGP tool with a unique dual-engine core: switch freely between the battle-tested GnuPG and a modern, memory-safe Rust rPGP backend. It makes encryption, signing, and key management easier and more trustworthy in everyday privacy workflows.