X.org releases version 7.3, gets hotplugging support

X.org is the underlying graphical workhorse that powers pretty much every desktop installation on Linux and Unix operating systems. Today marked the mildly delayed new release of X.org version 7.3, which corresponds to server version 1.4. The X.org community has been working out the last of the bugs since their code-base became semi-frozen on August 1st (which they refer to as "Code Slush") and are now confident that the release will be worth the wait. The so-called killer feature of this version of X is the new support for hotplugging of input devices (such as keyboard, mice, touchscreens) as well as output devices (monitors, projectors, and so forth).

These features have been missing for ages in X and have now been implemented thanks in large part to a few very dedicated developers. According to the X.org developers, kudos goes to Daniel Stone for the input hotplugging features, and to Keith Packard and Eric Anholt for implementing output hotplugging support. The input hotplugging allows communication with HAL or D-BUS to determine when a new input device has been attached to the system. The device should then ready to use right away. In addition, output hotplugging is acheived due to an updated version of the XRandR (X Resize and Rotate) Extension, which is still considered version 1.2 in this release even though it is much improved.

The input and video driver API/ABIs are not compatible with the previous server release, version 1.3, so you will not be able to mix and match drivers that were released for previous X server versions. There are a number of other features that have been added to this release, some of which can be seen at the X.org wiki.

While support for hotplugging has been a long time coming in X, it may be a few months before any of the Unix desktops have updated their code to take advantage of the new features in the underlying system. However, as the desktop environments make their next release one can expect that some user interfaces to control hotplugging and other features will start to crop up.