Learn what Roundcube webmail is, its open-source history since 2008, core IMAP features, plugin ecosystem, and why it is free to self-host on any server.
Roundcube is an open-source, PHP-based webmail client that gives any IMAP mail server a modern, AJAX-driven browser interface. First released as a stable version in March 2008 after development led by founder Thomas Bruederli, it has since become one of the most widely deployed self-hosted webmail front ends, bundled by default with hosting control panels such as cPanel and Plesk.
The project is licensed under GNU GPL v3 or later and has been fiscally and organizationally hosted under Nextcloud since 2023, following an earlier attempt at a full rewrite (Roundcube Next) with Kolab Systems that was funded via crowdfunding in 2015 but halted in 2016.
Roundcube supports full IMAP functionality including folder management, message search, spell checking, and MIME-compliant attachment handling, along with an integrated address book and a skinnable, desktop-like interface built on Ajax.
A documented plugin API allows administrators to extend Roundcube with features like calendaring, two-factor authentication, and custom branding, and the project bundles other open-source libraries such as TinyMCE for rich text editing and an HTML5-PHP sanitizer for security.
Roundcube itself is completely free and open source under the GNU GPL; there is no official paid tier, subscription, or per-seat license fee for the core software.
Organizations typically incur only hosting infrastructure costs, since Roundcube runs on a standard LAMP/LEMP stack; some managed hosting providers and hosting panels bundle Roundcube automatically as part of paid hosting plans, but that cost is for the hosting itself, not for a Roundcube license.
Yes. Roundcube is free and open source under the GNU GPL v3 or later, with no license fees for the core software.
Roundcube was created by Thomas Bruederli, with the first stable release announced in March 2008 after about two years of development.
No. Roundcube is a webmail client, not a mail hosting provider; it needs to be installed on a server and connected to an existing IMAP/SMTP mail server.
Roundcube Next was a planned full rewrite announced with Kolab Systems in 2015 and funded via a crowdfunding campaign that raised over $103,000, but the rewrite effort was halted in 2016.
Since 2023, the Roundcube project's organizational and fiscal home has been hosted under Nextcloud, alongside its original community of contributors.
Yes, Roundcube has a documented plugin API that allows features like calendaring, two-factor authentication, and custom branding to be added.
Roundcube runs on a standard LAMP or LEMP stack: Linux, a web server like Apache or Nginx, a database such as MySQL or PostgreSQL, and PHP.
Because it is free, self-hosted, and lightweight, hosting panels such as cPanel adopted Roundcube as a bundled webmail option, replacing older clients like SquirrelMail.