* New [backup format][backup-format] using scrypt key-derivation function
* Non-encrypted backups no longer supported
* [split VM packages][packages-split], for better support minimal, specialized templates
* [Qubes Manager decomposition][manager-ticket] - domains and devices widgets instead of full Qubes Manager; devices widget support also USB
* [More flexible firewall interface][vm-interface] for ease unikernel integration
* Template VMs do not have network interface by default, [qrexec-based updates proxy][qrexec-proxy] is used instead
* More flexible IP addressing for VMs - [custom IP][custom-ip], [hidden from the IP][hide-ip]
* More flexible Qubes RPC policy - [related ticket][qrexec-policy-keywords], [documentation][qrexec-doc]
* [New Qubes RPC confirmation window][qrexec-confirm], including option to specify destination VM
* Dom0 update to Fedora 25 for better hardware support
* Kernel 4.9.x
You can get detailed description in [completed github issues][github-release-notes]
Known issues
------------
* On some laptops (for example Librem 15v2), touchpad do not work directly after installation. Reboot the system to fix the issue.
* List of USB devices may contain device identifiers instead of name
* For other known issues take a look at [our tickets](https://github.com/QubesOS/qubes-issues/issues?q=is%3Aopen+is%3Aissue+milestone%3A%22Release+4.0%22+label%3Abug)
It is advised to install updates just after system installation to apply bug fixes for (some of) the above problems.
Downloads
---------
See [Qubes Downloads](/downloads/).
Installation instructions
-------------------------
See [Installation Guide](/doc/installation-guide/).
Upgrading
---------
There is no in-place upgrade path from earlier Qubes versions. The only
supported option to upgrade to Qubes R4.0 is to install it from scratch and use
[qubes backup and restore tools][backup] for migrating of all of the user VMs.
