Is Remmina free and open source?

Yes. Remmina is free and open source, and its own site goes further: it is copylefted and libre. That means you can use it at no cost, but also see, change, and share it. The project describes itself as "not only free as in gratis and Open Source, but also copyleft."

What "free" means for Remmina

The site makes a distinction that matters if you plan to modify or redistribute the software:

• Free as in gratis — you can download and use it without paying.
• Open Source — the source code is available.
• Copyleft — the license preserves those freedoms for others when the software is used, modified, or shared.

So Remmina is not just a free download with a closed codebase. The copyleft condition is the part that keeps it libre for downstream users.

Who makes and maintains it

Remmina is community-driven. The site says it is "lovingly made, funded, and translated by the likes of you" — meaning contributions, funding, and translations come from users and community members rather than a single vendor.

What you get with it

Remmina is a remote desktop client for accessing and sharing screens and files. According to the site, it supports these remote access protocol plugins:

It also lists features such as plugins, kiosk mode, and multi-monitor support.

Availability

The project states it is available in 67 languages and 50+ distributions, with YouTube installation guides for Linux distributions. That breadth is a practical signal of the community effort behind it.

Bottom line

If your question is whether you can use Remmina for free, modify it, and share it — yes, under a copyleft open source model. If you need the exact license terms for a specific compliance or redistribution scenario, check the license file in the project's source repository, since the site summary here does not name the specific license.