Best SIP3 Alternatives in 2026

Lightweight SIP proxy, location server, and registrar for a reliable and scalable SIP infrastructure.

Monitor, troubleshoot, and analyze every VoIP call with clarity.

PDF manager, viewer and editor offering a seamless user experience on multiple devices. It's designed to be minimal, fast, and easy to set up using Docker.

Document Management System with workflows, access rights, fulltext search, and more

Manga/comic/light novel media server with clients for Windows, Linux, macOS and Android

E-book library manager that can view, convert, and catalog e-books in most of the major e-book formats and provides a built-in Web server for remote clients

Build and manage a comic book library. Download, rename, move and convert issues of the volume to your liking

Cross-platform e-book/manga/comic/pdf server and web reader with user management, ratings and reviews, and metadata support.

Serve offline ZIM archives via a simple web server.

Media server for comics/mangas/BDs with API and OPDS support, a modern web interface for exploring your libraries, as well as a web reader

A fast, free and open source comics, manga and digital book server with OPDS support

Turnkey repository application providing durable access to digital resources

Digital document management system with a flexible metadata and workflow model primarily aimed at academic institutions

Robust and modular repository system for the management and dissemination of digital content especially suited for digital libraries and archives, both for access and preservation