- Linux is ONE OPERATING SYSTEM (OS). Although it is available as a multiplicity of systems branded as separate OS-es (unlike Windows or Mac), which are different in the sense that they are available for download as different BUILDS, that is systems containing the Linux kernel packed by different companies or communities, it is still the same system. Being the same operating system, all different builds can (at least theoretically) run the same programs.
- Only that the more programs you have the bigger the risk some of these will lead to conflicts, especially when they are meant to achieve the same task (not to say that some software may be explicitly incompatible with each other (but that is a normal and special case).
- The difference between different Linux distros appears with respect to the way these programs are made available. There may be also the case where some Linux system is based on a special way of compiling the kernel itself. In this case the kernel is also a piece of software that is "made available" in a different way. But for the general user experience, the difference in the way software is made available is with respect to the format in which software is packaged, the internet sources where software is present to be downloaded and updated ("repositories", "software sources"), and the installer programs adapted to the different formats and repositories. All these may differ between different Linux distributions, but will differ less when different distributions use the same Linux build (Debian, Arch, Ubuntu) and/or the same repositories (at least partially).
- The kernel itself may be different in the sense that different builds may use different VERSIONS of the Linux kernel. Also, Linux distributions differ in relation to the kernel version in the sense that some use one or other version of the kernel for their stable releases, while others (called rolling releases) update continually the kernel itself. But for the end user, especially for the beginner and intermediate user, the differences between different Linux OS-es will be in fact differences between the desktops environments used by the specific builds.
- A desktop environment is a graphical user interface (GUI) to use in interacting with your computer's operating system (OS) instead of using the command-line interface.
- Programs are more or less adjusted to certain desktop environments. I was surprised to see that a cross-platform application like Firefox was surprisingly less fitted in KDE desktop (used among others by Kubuntu, Opensuse, LinuxMint, PCLinux etc) because KDE uses the Qt interface instead the GTK (these are libraries to build graphical user interfaces, GUIs). When a GUI/DE is not written in GTK, a program which has a GTK GUI will fit less into a non-GTK environment. But those problems are limited to appearance mostly.
Each Linux distro has a different project idea which determines the choices made by its creators in all aspects. When choosing a Linux one has to consider the purpose of that project.
For example, I will mention some Linux operating systems and then define some differences between them.
The most known Linux OS are Ubuntu and Linux Mint. Other Linuxes are Manjaro, Elementary OS, Fedora, and many others.
But while I mentioned 5 Linux operating systems, in fact, three of them, Ubuntu, Elementary and Linux Mint are all based on the Ubuntu build, which is maintained by the company Canonical. Ubuntu is itself based on the Debian Linux DISTRIBUTION. Debian is available as a separate build itself, a rolling release, one using only open source software, meaning that it lacks a lot of drivers, for example. Ubuntu, which is not a rolling release (providing short-time and long-time versions of its distribution) provides the Debian-based build with some various drivers and applications, its own repository base (update sources), specific maintenance and development and, a large community. Taking advantage of all these, Linux Mint provides its own build, which means a streamlined Ubuntu (therefore non-rolling) with access to the Ubuntu repositories to install and update applications, but also with its own repositories ('repos'). (For this reason, many users consider Linux Mint as one as the best Linuxes, as it is a Linux improved both by Debian, Ubuntu, and the Mint company and community. But some who dislike Ubuntu, will also dislike Linux Mint.)
Ubuntu has a large community. It promotes different desktop environments. While Ubuntu is the basic OS in all the Ubuntu family, the distribution branded as Ubuntu proper uses its own desktop environment, called Unity: that is what you look and feel when in contact with Ubuntu. The difference is in the appearance, but also in the different things you can do and the ways you can do them. This means that the memory use is different.
KDE is the DE used by Kubuntu. KDE and Unity are the fancier and, as a consequence, the heavier on resources in the Ubuntu family. Xfce is a DE made to be used on computers with lower resources while keeping a rather stylish appearance - and is used in Xubuntu. LXDE - used in Lubuntu - is the lightest of the family - for even older computers theoretically, but keeping a feel that in my opinion is still more stylish than that of Windows XP, not to mention the speed. But while Unity is related to Ubuntu and Cnonical, KDE, Xfce and LXDE are only loosely related to Ubuntu/Canonical.
Ubuntu-proper = Ubuntu OS + Unity DE
Kubuntu = Ubuntu OS + KDE
Xubuntu = Ubuntu OS + Xfce DE
Lubuntu = Ubuntu OS + LXDE
Linux Mint also uses KDE and Xfce as the desktop, but also Cinnamon and Mate. Lately, there is a Mate edition of Ubuntu too.
Manjaro, on the other hand, is not based on Ubuntu, and not even on Debian, but represents a separate rolling distribution of the Linux kernel, with separate repositories. It is based in fact on Arch Linux and its repositories. Manjaro uses mainly KDE and Xfce as desktops.
Elementary OS is based on Ubuntu build and repositories, and therefore not a rolling release (in fact is one of the slowest in providing new releases) but uses its own desktop environment (Pantheon) and file browser. A user that is familiar with Xubuntu will find the same method of installing applications in Elementary, but otherwise this OS will look more different to him that does Manjaro-Xfce.
Also, Xubuntu will feel more familiar (if not identical) to a Linux Mint Xfce user than to a Ubuntu/Unity user. Manjaro Xfce will also feel familiar, until he tries to install programs: then, the AUR (Arch) repositories have to be used instead of the Ubuntu ones.
While Linux is one kernel, some differences appear between distributions depending on kernel, distribution and program versions, on the rolling or stable release, but also some new similarities appear based mainly on the desktop environments, and the final fact that there is one system and there are the same programs.
- On first confronted with Linux the shear diversity seems overwhelming, but after considering the above you realize this is an illusion in a way. The multitude of programs and the fact that most are opensource or free up to a point seems to encourage diversity. But the continuous change which is thus promoted tends to exhaust all possible combinations, and necessarily pushes diversity and novelty to its limit. After a while this continuous change, no matter the number of variables, leads to a clear monotony. We can change everything all the time and after a while this change becomes less and less important.
- What happens then? Not really a big surprise. After a while the Linux end-user seems bored with the variety and the lack of it. If you look for diversity you will end up feeling that Mac and Windows are more different from Linux and between themselves then one Linux is from other Linux. The Linux world is not infinite, Linux is not a magic realm, is a real (and ONE) operating system. Only better. Or is it? The fact is that it doesn't look like it. The continuous change and system-jump was compensating for something. If not for the lack of stability, then for the lack of the basic feeling of having a FINISHED PRODUCT. Most of them don't even try to seem finished or perfect. Linux is supposed to be perfect in itself and the user is supposed to feel guilty for not being able to achieve an outward customization as great as the inward mystical perfection of the kernel.
- There come the big winners of this contest. Ubuntu, Mint, OpenSuse, even ElementaryOS. They share some features between themselves and also with Mac and Windows. When they are criticized it is for the same reasons for which they are loved and successful. While Unity is criticized, KDE is not, although it has more obvious faults in my view. Elementary OS is praised by everybody. Why is that? Because they have the same advantages as Canonical's Unity, while the causes of their success, although similar, are more discrete for the present moment, and thus leave people keep their dreams and the utopian view that perfection can come out of the freeware paradise. To be even blunter: the more a Linux distro is closer to completion, the more it will resemble Mac and Windows. Even if Windows is basically the worst system out there, the fact that it is promoted and developed as one unified project has lead to a slow but real progress. If a Linux is to become a finished product, it needs a clear and unified project, witha clear and powerful will behind it. I doubt that without money and company governance that will ever occur.
- So, my advice would be to run around and try diversity (different builds, versions, desktops, themes and icons) but only expect real quality to come from focused projects.
- I think that diversity is preferable when changing a system for another, but it is not a good thing to be sought inside one system, by changing the defaults to something very different. If you want something different, try a different system. If you don't like Unity, go for a different system, don't install something else on top of that. If you want KDE, go for Kubuntu, don't install it on top of Ubuntu-proper. Even better, find a KDE-focused distribution (PCLinux, KaOS, Netrunner). If you really like Ubuntu, try to understand that Ubuntu is a project that decided to create Unity and that Unity will get the best support and integration, and that under Ubuntu only Unity has a chance of ever representing a FINISHED PRODUCT.
- Different projects promoted by specific groups and communities (recently, Ubuntu Mate has been recognized as part of the Ubuntu family) are admirable. But the end-user has to be aware that the beauty of these projects lays in their potential, which is not yet exploited, and that the foreseeable benefit is not yet there. In fact, it is a potential intended for developers, not for the users.
- Doing one thing but doing it well is a decisive principle that can be confirmed by experience. If you give a chance to a well-designed system and use it as it is without altering it too much you will only then see the unifying idea behind it. That is mostly clear for systems that value good design and perfection o detail. The one systems that excels in this sense is Elementary OS. It makes no point in altering that. It is already an alteration and a re-design of Ubuntu in view of a clearly visible goal. But Unity itself is a clear project not unlike eOS.
- If you don't care about looks but want stability, consider OpenSuse. But Unity is made for stability too, and if you add to that the good looks and the full desktop integration, it will be hard to find something better in fact!
- KDE is a very interesting environment and in full development. But it is so complex that it is difficult to have it as a cleanly streamlined product for any user. It looks great, and also has the discrete but present scent of geek-ness, and therefore may be irresistible to some. I should like it too, but I also wander why I admire eOS more, if not even Unity. I find KDE designed for the Linux-insiders, lacking the ultimate elegance that Linux needs to show in order to take over Mac and Windows. Compared to eOS, KDE is kitsch. It seems dominated by Compiz-like flashy effects (which are Plasma), which look both childish and outdated in spite of the new Plasma5 flatness. But those can be made discrete and a KDE system will be both stable, full-featured, customizable, and good looking in the end.
- Xfce is already number one for many users who like the Linux typical instability. On this tormented sea, it is light and highly customizable, while also being full-featured. It looks like a lighter and less flashy alternative to KDE, but it has the advantage of being closer to the family of Gnome desktops (using GTK, like Gnome2, eOS's Pantheon desktop, Cinnamon, Mate), while KDE has the advantage and disadvantage of being a separate world, with a lot of different dependencies. But Xfce is not completely polished by itself. There are some distros which try to promote a polished Xfce desktop, but they are not there yet.
- LXDE is even lighter than Xfce, but even less polished and not at all as well featured.
- Evolve OS will be a good surprise in 2015. While apparently imitating Chrome OS, they have taken from eOS: good looks, cleanness, simplicity of use, perfection of detail and stability. But they are based on Gnome 3, and that may in the end reflect on the use of resources. One needs a stable release to judge. If they succeed, it will be a revolution, because what is really special about Evolve OS is that it comes with its own completely separate Linux build, repositories, packages, DE, and installer. While eOS is based on Ubuntu in all these features.