What is new in Ubuntu 16.04 Desktop
Snap application format
Ubuntu 16.04 LTS introduces a new application format, the ‘snap’, which can be installed alongside traditional deb packages. These two packaging formats live quite comfortably next to one another and enable Ubuntu to maintain its existing processes for development and updates.
The general theme for 16.04 on the desktop is one of bug fixes and incremental quality improvements.
GNOME is mostly upgraded to 3.18. GLib upgraded to to 2.48 (corresponding to GNOME 3.20)
GNOME Software replaces Ubuntu Software Center. This brings a faster store experience and moves our archive metadata in line with Debian. It has been renamed "Ubuntu Software" to improve recognition for Ubuntu Software Center users.
All default applications and libraries ported to use WebKit 2
GNOME Calendar is now included by default
Empathy and Brasero are removed from the default installation
Chromium upgraded to version 48
Firefox upgraded to version 45
Online searches in the dash are now disabled by default
Improved HiDPI support in the greeter
Added more supported languages by default
Multiple bug fixes
Unity & Compiz
Improved launcher integration with file manager and devices
Support for formatting removable devices from quicklist
Improved support for gtk applications using headerbars
Improvements to the switcher and spread backends
Activate app spread by Super+Ctrl+W
Unity control center option to always show menus
Improvements to GNOME key grabbing
New dash overlay scrollbars
Better Dash theming support
Support for scaling cursors in HiDPI environments
Show icons launching state in launcher when apps launched elsewhere
Launcher can be moved to the bottom
LibreOffice 5.1 brings a lot of improvements to the entire package.
LibreOffice defaults to the Breeze theme in Ubuntu
Improvements in the Python scripting and language bindings
Support for WebDAV via HTTPS
Writer word processor
Added support for whitespace hiding. A long standing feature request.
Mailmerge in Writer can use spreadsheets as a data source
Spell check dialogue no longer auto closes
Exponential and power trend lines handle negative Y values
Performance improvements leveraging SSE3 for SUM functions
Added support for PNG export
Search for numbers as formatted/displayed
Slide transitions use OpenGL 2.1+ and new transitions added
Keyboard shortcuts for navigation and sorting
Screensaver inhibiting for KDE, XFCE, Mate
What is new in Ubuntu 16.04 Server
New in 16.04, the kernel crash dump mechanism now supports remote kernel crash dumps. It is now possible to send kernel crash dumps to a remote server using the SSH or NFS protocols.
Ubuntu 16.04 includes the latest OpenStack release, Mitaka, including the following components:
OpenStack Identity -- Keystone
OpenStack Imaging -- Glance
OpenStack Block Storage -- Cinder
OpenStack Compute -- Nova
OpenStack Networking -- Neutron
OpenStack Telemetry -- Ceilometer and Aodh
OpenStack Orchestration -- Heat
OpenStack Dashboard -- Horizon
OpenStack Object Storage -- Swift
OpenStack Database as a Service -- Trove
OpenStack DNS -- Designate
OpenStack Bare-metal -- Ironic
OpenStack Filesystem -- Manila
OpenStack Key Manager -- Barbican
OpenStack Mitaka is also provided via the Ubuntu Cloud Archive for OpenStack Mitaka for Ubuntu 14.04 LTS users.
Ubuntu 16.04 also includes the first GA release of of the Nova driver for LXD (‘nova-lxd').
WARNING: Upgrading an OpenStack deployment is a non-trivial process and care should be taken to plan and test upgrade procedures which will be specific to each OpenStack deployment.
Libvirt has been updated to the 1.3.1 release.
Qemu has been updated to the 2.5 release.
Open vSwitch 2.5.0
Ubuntu 16.04 includes the latest release of Open vSwitch, 2.5.0. This is also an LTS release of Open vSwitch.
Ubuntu 16.04 also includes support for Open vSwitch integrated with DPDK (Data Plane Development Kit) enabling fast packet processing through userspace usage of compatible networking cards -- see the openvswitch-switch-dpdk package for more details.
Ubuntu 16.04 includes the latest release candidate (10.1.2) of the Ceph Jewel stable release; An update to the final release version will be delivered as an SRU to Ubuntu 16.04.
Ubuntu 16.04 includes version 1.9.15 of the Nginx web server, with an expectation to provide the next stable release of Nginx, 1.10.0, as an SRU after release (which will be virtually identical to 1.9.15). This version of Nginx also includes HTTP/2 support, which supersedes SPDY support previously provided in the Nginx packages.
Ubuntu 16.04 LTS includes LXD, a new, lightweight, network-aware, container manager offering a VM-like experience built on top of Linux containers.
LXD comes pre-installed with all Ubuntu 16.04 server installations, including cloud images and can easily be installed on the Desktop version too. It can be used standalone through its simple command line client, through Juju to deploy your charms inside containers or with OpenStack for large scale deployments.
All the LXC components, LXC, LXCFS and LXD in Ubuntu 16.04 LTS are at version 2.0.
docker was upgraded to the version 1.10. Note that this requires migration of existing images to a new format which will be performed on the first start of the service. This migration can take a long time and put a high load on the system.
PHP was upgraded to 7.0. Note that this will require modifications to custom PHP extensions and may require modifications to PHP source code.
NGINX and PHP 7.0
Upgrading from prior version of Ubuntu with PHP5 FPM configurations and NGINX will require a manual configuration change.
Most PHP-dependent packages were either rebuilt or upgraded for PHP7.0 support. Where that was not possible, packages may have been removed from the archive. There was one exception, Drupal7.
Drupal7 does not pass upstream testing with PHP7.0 as of the 16.04 release . An SRU will be provided once upstream PHP7.0 support is available and verified. Until that time, the drupal7 package will not be installable in 16.04.
MySQL has been updated to 5.7. Some configuration directives have been changed or deprecated, so if you are upgrading from a previously customised configuration then you will need to update your customisation appropriately.
Password behaviour when the MySQL root password is empty has changed. Packaging now enables socket authentication when the MySQL root password is empty. This means that a non-root user can't log in as the MySQL root user with an empty password.
Juju and Juju UI have been updated to 2.0beta4. The final Juju 2.0 release will come via an update post-release. The package name is juju-2.0. Juju 1.25.5 is available in the juju package for existing production environments.