Language Selection

English French German Italian Portuguese Spanish

X Factor - understanding the X window system

Filed under
Software

X was originally created in the mid-80s by a research group from MIT. Its goal was to create a windowing system quite unlike any that had been conceived before. Thus X's design differs greatly from that of other windowing systems, having designed-in support for many elements which are unique ­ features which in fact are nowadays often being hacked into other windowing systems.

More often than not, such attempts are kludgy and don't work well, because they lack the ground-up desig X offers.

X went through a number of iterations because the original releases were not under a copyleft license. Every Unix developer created his own version, usually only modifying small parts, resulting in divergence into many incompatible versions, most of which fell under proprietary licences.

As a result, a standards body was eventually created to oversee the development of X. This body, known as the X Consortium, includes amongt its members IBM, Hewlett Packard and even Microsoft.

The X server has two important functions. Firstly, it speaks to the hardware; this means the X server needs to contain the driver for your graphics card, mouse, keyboard etc. Secondly, it speaks to X clients (every X program, from xterm to OpenOffice.org is an X client). Thus no X client ever talks directly to the hardware.

The most common channel is Unix Domain Sockets (UDS, a very fast mechanism for interprocess communication on Unix) which provides the highest speeds for local usage (for example where the X server and X clients are on the same machine). However it can also run over several network protocols, such as TCP/IP, allowing you to use your local X server to run a program on a distant machine over the Internet.

Luckily, working directly with the X protocol is seldom needed because X also provides xlib. Xlib is essentially a library of standard X tasks, such as basic drawing primitives and event handling. Xlib is written in C (with wrappers to many languages) and it in turn speaks to the X protocol for you. Xlib takes care of the low-level detail part of using the X protocol, such as establishing a connection over the appropriate channel and talking to the server.

Today the two most important widget sets in the Linux world are GTK and QT respectively. Their importance is greatly enhanced by the fact that these are the two toolkits on which the Gnome and KDE desktops are respectively built. Many other widget sets exist, and although none are as feature-rich as GTK or QT, they are still often used.

The two most important desktop environments today are of course KDE and Gnome, as most new Linux applications are built for one or the other. Currently KDE and Gnome basically match each other for features and which one a user prefers tend to be a matter of taste rather than a technical decision. Almost all Linux users use one of these two. Old-time Unix users and programmers often shun them however, preferring minimalist desktops.

Full Article.

More in Tux Machines

Cinnamon 2.4 to Feature New Theme Selection and Options for Linux Mint 17.1

Cinnamon is the default desktop environment in Linux Mint and it's built by the same developers who are making the Linux distro. It stands to reason that the best implementation for Cinnamon will be on Linux Mint. It's also the place that integrates the latest updates for Cinnamon as soon as they are made available. Usually, the latest iterations of Cinnamon are integrated quickly in Mint, but the developers are also working on an updated Linux Mint version, 17.1. The new Cinnamon 2.4 DE might arrive there by default and not in Linux Mint 17. Read more

Knoppix 7.4.1 Is Now Available For Download

Knoppix developers have released a major version of their operating system Knoppix 7.4.1 based on the usual picks from Debian stable (wheezy) and newer Desktop packages from Debian/testing and Debian/unstable (jessie). According to the official release note, this distro version uses kernel 3.16.2 and xorg 7.7 (core 1.16.0) for supporting current computer hardware. Read more

First Tizen phone now expected in India

Samsung’s postponed Tizen Linux-based smartphone is now heading for a launch in India by the end of the year, reports India’s Economic Times. Everybody, it seems, wants a piece of the Indian smartphone market. The latest company with plans to jump headlong into South Asia is Samsung, which aims to ship a Tizen Linux-based smartphone in India after the Diwali festival in November, according to the Economic Times (ET). Read more

GNOME: 3.14 almost there

Speaking of gedit, after the major changes of 3.12, 3.14 has been a cycle focused on stabilization and polishing. Overall the revised user interface got mostly positve feedback.. I for one, as a heavy gedit user, adapted to the new UI without problems. 3.14 will have a few incremental changes, that among other things try to address some of the issues pointed out by Jim Hall’s usability study presented at GUADEC: “Open” will be a single button removing the dichotomy between the open dialog and recent files and providing quick search among recent files. “Save” now uses a text label since it turns out a lot of people did not grok the icon (and no, I am not going back to the floppy image!) and the view menu has been reorganized and now uses a popover. With regard to the “Open” button, we know things are not perfect yet, search among recent is great, but when the “cache misses”, going through a double step is painful… we already have a few ideas on how to improve that next cycle, but for now I can vividly recommend to try the “quickopen” plugin, one of the hidden gems of gedit, which already provides some of the things we would like to integrate in the next iteration. Read more