Desktop environments for Linux are not released ready-made. Behind each is a set of assumptions about what a desktop should be, and how users should interact with them. Increasingly, too, each environment has a history -- some of which are many years old.
As you shop around for a desktop, these assumptions are worth taking note of. Often, they can reveal tendencies that you might not discover without several days of probing and working with the desktop.
Here, for example, are the assumptions and intentions behind seven of the most popular Linux desktops today:
Linux Mint introduced the Cinnamon desktop as "The GNOME 3 Replacement," promising ease of use and a desktop based on the features that users wanted.
What this approach means is a classic desktop with a well-rounded set of administrative and configuration tools. Although innovations such as overviews for file and virtual desktop selection are sometimes part of new releases, and Cinnamon is starting to develop a KDE-like set of panel and desktop applets, the desktop's emphasis is usually on tweaks to improve everyday use.
For example, in the latest release, the software updater includes a descriptive Type column, as well as a description of the available kernels designed to make selecting more intelligent than a simply choice of the latest release.
New users should have no trouble using Cinnamon, but I suspect that hands-on users of at least intermediate expertise are more likely to appreciate its careful habit of incremental improvements. More than any of the other major environments today, Cinnamon listens to users and gives them what they want.
Like KDE, GNOME started as a general desktop and encouraged an ecosystem of utilities and applications. That ecosystem is a study in minimalism, suitable for most everyday uses, but occasionally lacking in advanced cases. It is wildly popular, supporting a majority of the desktop environments mentioned here.
The GNOME desktop environment itself is a more mixed story. With the GNOME 3 release series, GNOME discarded the classical desktop model. Instead, it emphasized removing clutter, which the designs defined as desktop and panel options, and other traditional elements, and automated the assignment of applications to virtual workspaces. In most cases, applications open maximized, and working with two applications at once can be awkward until you learn the tricks.
In addition, modern GNOME uses two main overviews: the one in which you work, and the one in which administrative tasks such as launching applications and manually adjusting workspaces are done.
These design elements can be modified by extensions. Use enough of them, and GNOME 3 becomes a classic desktop -- or just about anything else, if you have the patience for experiments that result in what other environments offer upon installation.
As intended, GNOME is most likely to appeal to those who prefer to work on one thing at a time, and without distractions. Phone and tablet users are also more likely to accept the two overview model than those whose main computer is a laptop or workstation. However, many distributions install GNOME with several extensions, so you are not likely to see GNOME as its designers originally wanted.
KDE began as an effort to be all things to all levels of users. Its goal remains unaltered after eighteen years, which is both a strength and a weakness.
On the one hand, you can set up a basic desktop as quickly as with any other environment, yet still find ways to enhance it and your workflow. KDE is especially strong on customization, with features to alter basic window and desktop behaviors that other desktops have never attempted.
Once you have a basic desktop, you can choose to move on to intermediate features such as multiple icon sets or task-oriented desktops, or advanced ones like KRunner, a menu substitute for those who can find their way around KDE blindfolded.
Alternately, you can stay where you are. Unlike GNOME or Unity, KDE makes no assumptions about the best way to work. Instead, it gives you tools to adopt to your purposes or ignore as you think best.
On the other hand, the weakness to this approach is that it can be overwhelming. Newcomers are presented with so many options that, unless they are aware that they can filter out most options from their attention, they are as likely to be intimidated as enticed.
Similarly, KDE applications have a tradition of including every possible feature their users are likely to need. Applications like Amarok, K3B, or digiKam are famous -- and sometimes infamous -- for their completeness. At times, this insistence on including everything leads to disorganization in the menus that can take several releases to correct.
If you customize heavily, prefer to work your way, and like the idea of growing at your own pace, chances are you will feel comfortable in KDE. By contrast, if you prefer simplicity, or only want a desktop for launching apps, then KDE has aspects of nightmare.