<span class="application">VirtualBox</span> has a free software version, called <span class="application">VirtualBox Open Source Edition</span> and some proprietary components, for example to add support for USB devices.
XXX: VirtualBox Guest Additions has been removed since Tails 4.27. Without Guest Additions, the shared folders feature of VirtualBox is unavailable.Until Guest Additions is added back (#18728), the tip below shouldn't be displayed.
<p>With the <a href="https://www.virtualbox.org/manual/ch04.html#sharedfolders"> <span class="guilabel">shared folders</span></a> feature of <span class="application">VirtualBox</span> you can access files of your host system from within the guest system.</p>
<p>Microsoft Windows and macOS being proprietary software, they cannot be considered trustworthy. Only run Tails in a virtual machine on Windows or macOS for testing purposes and do not rely on it for security.</p>