Canonical pushed out Ubuntu 14.04 last week. This release is the first Ubuntu Long Term Support release in two years and will be supported for the next five years.

It feels like, for Canonical at least, this Long Term Support release couldn't have come at a worse time. The company is caught in a transitional phase as it moves from a desktop operating system to a platform that spans devices.

The problem for Canonical is that it's only about 90 percent of the way to a platform-spanning OS, but it just so happens that the company's schedule calls for a Long Term Support release now.

Long Term Support releases are typically more conservative and focus on stability and long-term maintenance rather than experimental or flashy new features. Things that are 90 percent done don't make it into LTS releases. And, unfortunately for Canonical, most of its foundation-shaking changes to Ubuntu are currently only about 90 percent done and thus not part of this release.

The two biggest changes on the horizon are the Mir graphics stack and Unity 8, neither of which are part of 14.04.

Mir just isn't ready for primetime yet, and even the halfway step of xMir (which falls back to the X display server when it needs to) isn't ready enough to land in an LTS release. Were this not an LTS release, it seems likely xMir at least would be included. As it stands, the graphics stack in 14.04 is—aside from incremental upgrades—the same as it was in last year's 13.10.

Likewise, Unity 8 will not make its debut in this release. The next version of Ubuntu's flagship UI isn't quite there yet, at least on the desktop. Now, this puts Canonical in the unfortunate position of needing to support Unity 7 on the desktop for five years going forward.

Ubuntu is planning to ship its first mobile devices later this year, which will use Unity 8, since the mobile version is much further along than the desktop. Thus, when Ubuntu Mobile launches, Canonical will find itself having to maintain two separate platforms, both Unity 7 and 8, with Unity 7 desktops hanging around for a minimum of five years.

While Ubuntu 14.04 might be most notable for what it is not—namely the next-generation version of the Ubuntu desktop—it is nevertheless an important update, because for those users sticking with LTS releases, it represents the first major change in two years. And a lot has happened in Ubuntu land in the time since 12.04 was released.

There have been major leaps forward in the form of upstream kernel updates, application updates, and several major user interface changes in Unity.

It's also the first time LTS users will have to deal with the Amazon Search Lens and Ubuntu's new privacy policy.

The kernel

At the core of Ubuntu 14.04 is the Linux kernel 3.13.0-24.

The previous release, Ubuntu 13.10, used the 3.11 kernel, and the last LTS release, 12.04.4, currently ships with 3.8. A lot has changed since 3.8, primarily in the form of better hardware support, but there are some welcome improvements in this latest kernel release even for those already running 3.11 in Ubuntu 13.10.

How much the kernel update impacts your Ubuntu experience will depend a little bit on your hardware. For example, if you've got dual GPU hardware that uses Nvidia Optimus to switch between GPUs—one optimized for performance and the other for conserving power—the move from 12.04 to 14.04 will be huge. As of the 3.12 kernel, there's now low-level support of GPU switching (which should happen automatically).

Users with SSD-based machines should see better performance in this release, partly because of some improvements in the kernel, but also because Ubuntu now ships with TRIM features enabled by default. There are some horror stories about TRIM support in Linux floating around the Web, but those issues have largely been solved.

That means you can delete those cron jobs running the fstrim command and stop worrying about adding "discard" to all your fstab entries. Ubuntu 14.04 will handle this automatically, right out of the box. If you're running Ubuntu on an SSD, you will likely notice a speed improvement, particularly in anything that requires a lot of data being written to disk.

Another of the headline-worthy changes in the 3.13 kernel is the addition of support for nftables, which will eventually replace the iptables firewall tool. Nftables is more than just a replacement for iptables, it's a complete reworking of the way the kernel handles packet filtering. Right now nftables is not quite ready for prime time, and the command line tool nft is not installed by default. But when the 3.15 kernel rolls around (which will be well within the lifespan of Ubuntu 14.04) nftables can replace your iptables-based firewall.

Battery life improvements

Power management remains one of the weak points in Linux, with battery life lagging far behind what you'll find in Windows and OS X running on the same hardware.

The good news for laptop users is that several recent kernel updates related to power management have dramatically improved battery life, and these are all part of Ubuntu 14.04.

I started using 14.04 when the final beta was released in March and immediately noticed a huge difference in battery life on my primary machine, an early-2013 Retina Macbook Pro. It's hard to say whether these improvements come from the kernel updates or perhaps some Unity-level improvements, but whichever is responsible, it's a big improvement over Ubuntu 12.04.

I typically use only a handful of apps, primarily a Web browser—Chromium with anywhere from 20 to 80 tabs—and a Terminal session with several Tmux sessions running inside it, which I attach and detach depending on what I'm doing (for development and writing I run zsh, python, ruby, vim, mutt, cmus). None of that should produce a huge battery drain. I also occasionally use Darktable and Gimp for image editing, which of course shortens the battery life. I should note that I use a Chromium add-on that suspends background tabs and significantly reduces Chromium's overall system footprint even with the large number of tabs I typically keep open.

This setup, which is pretty minimalist in terms of battery draining apps, would still manage to drain the battery in under four hours in Ubuntu 12.04, sometimes not lasting much more than three hours. I switched to running Ubuntu in VMware (using OS X as the base system), and battery life improved somewhat, consistently lasting about four hours, but that's still not very good.

In 14.04, with the same workload on the same machine, the battery lasts just over 4.5 hours on average. That's actually a pretty significant improvement and would be worthy of praise did it not still lag far behind OS X (6.5 hours) and the minimalist Crunchbang Waldorf (currently my primary OS), which lasts nearly as long as OS X itself—well over 6 hours. Crunchbang and Ubuntu share the same Debian core and Linux kernel, which most likely makes Ubuntu's Unity interface the primary source of the additional battery drain.

That's been my experience with battery life thus far in 14.04, but remember that real-world battery stats are highly subjective. Hardware, system setup, and the details of what you do make it nearly impossible to guarantee anything. That said, based on my experience with 14.04 on three different laptops, you'll likely see at least some improvement over 13.10 and even more so if you're upgrading from 12.04.