This release constitutes the first major version release of the X Window System in over a decade. The main reasons for the major version bump from 6 to 7 is that we have moved from what has traditionally been a source codebase comprised of many different components brought together into a single monolithic tree to a source codebase where each of those same components found in the monolithic tree are now split into logical modules that can be developed, built and maintained separately, but still fit together coherently into the larger project. At the same time, we have moved away from the imake build system to an autotools build system. By making these changes we have opened the source code up to a new generation of developers that can continue to build upon the long tradition of the X Window System.
The reason for having simultaneous releases for both the monolithic and modular trees is to allow for a transition period as developers, builders and vendors incorporate the significant changes to how the tree is built and developed into their products and to allow time for additional platforms to be supported the modular tree. This initial modular release has support for Linux and Solaris. During the transition period, we expect both the monolithic and modular trees to coexist. For the monolithic tree, we expect that there will be maintenance releases in the X11R6.8.x and X11R6.9.x series as needed. However, the main development effort will move over to the new modular tree.
The X11R7.0 release is the first in the modular series. One of the advantages of the modular tree is that it allows for more rapid and independent updates of module components, so full maintenance releases will no longer be required for simple bug fixes. Rather, each module component maintainer can prepare new releases as needed. These module component releases will then be periodically "rolled up" into official X.Org Foundation releases. The next official release will be X11R7.1 and is expected in mid 2006.
For more information on the modularization effort see the Modularization Proposal, and for help with how to build and develop in the new modular tree see Modular Developer's Guide.
We encourage you to submit bug fixes and enhancements to freedesktop.org's bug tracking system using the xorg product, and to discuss them on xorg@lists.freedesktop.org .
The release numbering is based on the original MIT X numbering system. X11 refers to the version of the network protocol that the X Window system is based on: Version 11 was first released in 1988 and has been stable for 17 years, with only upward compatible additions to the core X protocol, a record of stability envied in computing. Formal releases of X started with X version 9 from MIT; the first commercial X products were based on X version 10. The MIT X Consortium and its successors, the X Consortium, the Open Group X Project Team, and the X.Org Group released versions X11R3 through X11R6.6, before the founding of the X.Org Foundation in early 2004.
The next section describes what is new in the latest version (6.9/7.0) compared with the previous full release (6.8). The other sections below describe some of the new features and changes between 3.3.x and 4.0. There are lots of new features, and we definitely don't have enough space to cover them all here.