Kloxo is a free, open-source (AGPL v3) hosting control panel, formerly Lxadmin, installing on RHEL 8/9-family systems with about 130 one-click apps and switchable Apache/lighttpd and BIND/djbdns stacks, suited to budget virtual hosting.
BlueOnyx is an Italian open-source server management panel that is free with no license fees, running on AlmaLinux/RHEL with built-in email, DNS, virtual hosting, and API.
Cockpit is a Red Hat-sponsored open-source web server management console (LGPL v2.1+) supporting Fedora, RHEL, Debian and Ubuntu, offering free management of system services, storage, networking, VMs and containers.