When comparing i3 vs Gala, the Slant community recommends i3 for most people. In the question“What are the best window managers for Linux?” i3 is ranked 1st while Gala is ranked 6th. The most important reason people chose i3 is:
Every feature is thoroughly documented (including examples), and documentation is kept up-to-date. For questions that are not answered by the i3 [user guide](http://i3wm.org/docs/userguide.html), because they concern tools outside of i3 for example, there is the community [question & answer site](https://faq.i3wm.org/).
Ranked in these QuestionsQuestion Ranking
Pro Fully configurable (including tiling)
One of the biggest attractions of i3 is that it can be configured just about any way the user likes. Ranging from custom keyboard shortcuts to placement of opened apps, it is up to the user as to how they would like their window manager to behave.
Pro Easily switch to and manage floating windows
i3 can allow for the user to manage floating windows. Floating mode can be toggled by pressing $mod+Shift+Space. This way the user can take advantage of tiling as well as floating windows, all in the same session.
Pro Easily readable plain-text configuration
i3 has plain-text configuration, meaning that no lua or haskell is needed. This makes it rather easy to recommend i3 to other people without worrying whether or not they have the knowledge to configure it as it can be read by anyone without prior knowledge.
Pro Can tab windows
i3 permits tabbing through windows by turning on tab mode with $mod+w.
Pro Fast, especially on weaker hardware
Tiling means there are no fancy compositing or window effects to take up system resources.
Pro Can stack
i3 allows for stacking of windows in its environment.
Pro No window gap
Space is not wasted by separators, therefore making the most of the confined space on smaller monitors.
Pro RandR support
RandR provides more information about your outputs and connected screens than Xinerama does. To be specific, the code which handled on-the-fly screen reconfiguration (meaning without restarting the X server) was a very messy heuristic approach and most of the time did not work correctly — that is just not possible with the limited information that Xinerama offers (just a list of screen resolutions and no identifiers for the screens or any additional information). Xinerama simply was not designed for dynamic configuration.
Pro Can be reloaded quickly and configured without a client restart
Just two hot keys: Shift+Super+C to reload the config and Shift+Super+R to restart (which takes less than one second). Restarts pick up new versions of i3 or the updated config file, so you can upgrade to a newer version or quickly see the changes to i3 without quitting your X session.
Pro Sane development process
i3 uses test driven development with an extensive test suite to prevent bugs from ever happening again. All external contributions require a thorough code review to guarantee a certain level of quality.
Pro Terminal bell can be used to notify of completed actions
Terminal-bell gets passed through and marks the workspace visibly.
Pro Awesome multi-monitor support
User can assign specific workspaces to specific displays as well as apps to workspaces. This makes possible opening set of most used apps with 1 shortcut always on the same screens.
Pro Simple to use
Configuration is nearly automatic and simple, which can be really helpful to beginners.
Pro VIM Style key bindings
You can configure i3 so that your keys for moving windows is similar to vim, for example, M-j to move the window down.
Pro Great choice for keyboard users
The user keeps their hands in one spot (most of the time). One will find that the mouse is used less and less, making navigation quicker over time.
Pro Works with Gtk client-side decorations
The current bets of elementary OS (Freya) has enabled the use of Gtk client-side decorations.
Pro Beautiful, uniformly designed, and sleek
Gala is designed to be unimposing while still remaining functional and pleasant to look at. By following the elementary OS design guidelines, Gala maintains a very consistent look.
Pro Easy for Linux beginners who are coming from legacy OSs
Gala has limited configurability which keeps things simple.
Pro Hotcorners give shortcuts for multitasking, window management, or custom commands
User-configurable hotcorners means power users get four super easy shortcuts for multitasking, window management, or custom commands.
Pro Integrated compositing manager allows for fancy effects and animations
The Gala compositing manager allows for effects and animations to be used on a window by window basis.
Pro Dynamic workspace management
Workspaces are added and removed on the fly so you only have as many as you need at any given time.
Pro Innovative multitasking
Gala takes some hints from mobile OSes, but handles multitasking in a powerful way designed for desktop. Workspaces and alt-tabbing work well and are familiar, but feel smoother than alternatives.
Pro Extremely fast
Gala works well on limited-resource hardware, e.g older netbooks and Chromebooks.
Pro Excellent stability
Despite the current stable release only being on version 0.2, it is very stable.
Con Missing "include" possibility in config
While pretty good and easy to use for common tasks, the configuration language is missing the
include directive common in other languages. You can use a workaround - a shell script to config parts on demand. It would be best if this were built-in however.
Con Poor floating window support
Sometimes this is necessary, even when the Dev rejects feature requests. Firefox child windows (option dialog) is an example.
Con No window gap option
You can do a lot with i3 but the official version lacks the option to have gaps between windows. However, there's a fork called i3-gaps that is almost the same as i3 except the fact that it lets you have gaps between windows.
Con Steep learning curve
Has a steep learning curve for beginners.
Con It has some issues with transparency
Using transparent windows can cause them to crash.
Con Not very configurable
Unlike XMonad or Awesome, i3 can't be configured in a turing complete language, so it is much harder to alter its core functionality to do exactly what the user wants.
Con Documentation is online
Can't access it offline unless you download the page.
Con The plain-text configuration may not be suitable for beginners
i3 is configured through a plaintext configuration file. While it's very powerful and easy to learn, it may not be entirely user-friendly for those who have never edited a text configuration.
Con Manual tiling
The layout isn't automatic. The user must move panels manually and may indeed end up spending time on that rather than on working with the application.
Con Hard to install on some distros
While Elementary OS has Gala built-in, it might be difficult to set it up on certain distributions because it's tailored to Elementary OS only. Arch, for example, only supports Gala via AUR at the moment.
Con Limited configurability
Configuration options are few and far between and require editing settings with dconf editor.
Con Not very lightweight
Although it certainly does not eat up CPU or RAM, it is not as lightweight on resource usage as awesome, i3, openbox, for instance. This shouldn't really be a surprise however.
Con Buggy with nVidia Graphics
It's fantastic with the Intel integrated graphics; however, it is not good on nVidia ones
Con Does not render well under AMD graphics
The underlying compositor is know to have issues with AMD graphics cards, leading to poor performance, stuttering, and graphical artifacts.