With 6,700 GitHub stars, 79 releases, and 40 contributors since its October 2023 launch, OpenSign delivers a fully free electronic signature platform that removes the per-envelope pricing and seat limits of commercial e-signing services. The React-based frontend provides a drag-and-drop interface for placing signature fields, initials, date stamps, text inputs, and checkboxes onto PDF documents, while the Parse Server backend built on Node.js handles document routing through configurable multi-signer workflows with sequential or parallel signing order. Guest signers authenticate via one-time-password email verification without requiring account creation, while registered users manage documents through OpenSign Drive — a centralized vault with folder organization and status tracking across draft, in-progress, completed, and declined states. Every signing action generates tamper-proof audit trails logging timestamps, IP addresses, email addresses, and phone numbers, culminating in a detailed completion certificate attached to the finished document. The REST API v1.2 exposes endpoints for document creation, template dispatch, self-signing, and real-time webhook notifications on document lifecycle events, with regional deployments available in US and EU. PDF templates with pre-placed widgets enable repeated dispatch to different signers in a single API call. Custom branding controls email invitation templates, signing page appearance, and completion certificate styling. Deploy via Docker Compose with MongoDB, Caddy reverse proxy, and automatic HTTPS provisioning. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3 licensed.

PdfDing turns a scattered folder of PDFs into a proper library you can read, annotate, sign, and share from any browser. The viewer remembers exactly where you stopped in every document, so a manual opened on your desktop resumes mid-page on your phone, and progress bars in the library show how far you have read at a glance. Workspaces and collections group related documents, multi-level tags classify them, and starring, archiving, and bulk actions keep even a large archive tidy. Inside the viewer you can add text, highlights, and freehand drawings, then review and export your highlights and comments from dedicated sections and attach Markdown notes to a document. A signature you create once is stored on your server and waits for you on every device, ready to drop onto contracts and forms. Sharing a collection or a single PDF takes a link or a QR code, with optional access control over who can open it and for how long. Accounts are protected by OIDC single sign-on and two-factor authentication with TOTP or WebAuthn, and dark mode, an inverted color mode, and multiple layouts keep long reading sessions comfortable. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.