Cygwin/X User's Guide Harold L Hunt, II Jon Turney Copyright (c) 2000 Harold L Hunt II. Copyright © 2009, 2010, 2011, 2012 Jon Turney. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". __________________________________________________________________ Table of Contents 1. Cygwin/X Overview 2. Setting Up Cygwin/X Installing Cygwin/X 3. Configuring Cygwin/X Configuration overview Windowing mode Command line parameters XWinrc configuration file 4. Using Cygwin/X Starting Cygwin/X Starting Cygwin/X in multiwindow mode (startxwin) Starting Cygwin/X in windowed mode (startx) Other startup methods Switching out of Cygwin/X Stopping Cygwin/X Window managers Windows Clipboard integration Shared memory support Displaying remote clients Secure ssh Insecure telnet or rsh (Not recommended) Remote sessions via XDMCP Hardware Accelerated OpenGL (AIGLX) Input internationalization Compose key ('Multi_key') Input Method Editors (IMEs) Terminal Server or Fast User Switching A. GNU Free Documentation License 0. PREAMBLE 1. APPLICABILITY AND DEFINITIONS 2. VERBATIM COPYING 3. COPYING IN QUANTITY 4. MODIFICATIONS 5. COMBINING DOCUMENTS 6. COLLECTIONS OF DOCUMENTS 7. AGGREGATION WITH INDEPENDENT WORKS 8. TRANSLATION 9. TERMINATION 10. FUTURE REVISIONS OF THIS LICENSE How to use this License for your documents Colophon __________________________________________________________________ Chapter 1. Cygwin/X Overview Cygwin/X is a port of the X Window System to Cygwin. The Cygwin library provides a UNIX-like API on the Win32 platform. __________________________________________________________________ Chapter 2. Setting Up Cygwin/X Installing Cygwin/X Cygwin has a nice setup program that downloads and installs the necessary Cygwin packages for you. 1. Open the Cygwin, http://cygwin.com/ page in your web browser 2. Click on the "setup.exe" link. This link downloads setup.exe from the primary Cygwin server; save setup.exe to the directory that you would like to store the downloaded packages in (e.g. c:\download); do not save setup.exe to c:\cygwin, as that is the default directory for the extraction and installation of the downloaded packages. 3. Run setup.exe, you will see the welcome screen: [cyi01welcome.png] 4. Click Next to proceed to the next screen. 5. Choose, Install from Internet, this will still save the package files to your download directory so that you can install Cygwin on any number of machines: [cyi02installoption.png] 6. Click Next to proceed to the next screen. 7. The default Install Root is c:\cygwin which should be fine for most installations. Leave Default Text File Type as UNIX. Leave Install For set to All unless you lack local administrative privileges. [cyi03installto.png] 8. Click Next to proceed to the next screen. 9. Local Package Directory should default to the directory that you ran setup.exe from: [cyi04directory.png] 10. Click Next to proceed to the next screen. 11. Choose your proxy setup, or, just choose Direct Connection if no proxy is needed: [cyi05proxy.png] 12. Click Next to proceed to the next screen. 13. Select your nearest mirror for downloading: [cyi06mirror.png] 14. Click Next to proceed to the next screen; setup will download a list of available packages as it moves to the next screen. 15. On the next screen you will select the packages that will be downloaded and installed. A listing of the Cygwin/X packages is given below; a listing of the general Cygwin packages would be beyond the scope of this document. Cygwin/X packages are located in the X11 category. + xorg-server (required, the Cygwin/X X Server) + xinit (required, scripts for starting the X server: xinit, startx, startwin (and a shortcut on the Start Menu to run it), startxdmcp.bat ) + xorg-docs (optional, man pages) + X-start-menu-icons (optional, adds icons for X Clients to the Start menu) + You may also select any X client programs you want to use, and any fonts you would like to have available. + You may also want to ensure that the openssh package is selected if you wish to use ssh connections to run remote X clients. + You may also want to ensure that the inetutils or rsh packages are selected if you wish to use telnet or rsh connections to run remote X clients. (not recommended) [cyi07packages.png] 16. Click Next to begin the download process, you may want to try another mirror if you see a "Connecting" message on this screen for a long period of time: [cyi08downloading.png] 17. After the packages are downloaded, setup will automatically begin to install them: [cyi09installing.png] 18. I highly recommend allowing Cygwin Setup to create Desktop and Start Menu icons for you; these icons simply launch a bash shell: [cyi10createicons.png] 19. Click Finish to close the setup program. You have now successfully installed Cygwin/X. __________________________________________________________________ Chapter 3. Configuring Cygwin/X Configuration overview Cygwin/X settings are configured primarily through command-line parameters passed to X. A XWinrc file is used to configure the notification area icon menu, and customize window appearance in multiwindow mode. __________________________________________________________________ Windowing mode Cygwin/X can be configured to present X windows for an X screen in three different ways: * Windowed or rooted mode. (default) Each X screen appears as a single Windows window and all X windows are contained within those windows. (the Windows window contains the X root window for the screen) Note: This is typically used to present a virtual full-screen X session using the X window manager of your choice, or for remote XDMCP sessions. The -nodecoration option can be used to remove the Windows window decorations from the X screen window. Alternatively, the -fullscreen option can be used to show the X screen in exclusive fullscreen mode. * Multiwindow mode. (-multiwindow) Each top-level X window appears in its own Windows window. Note: This is typically used to work with local or remote X applications, integrated into your native Windows desktop. * Rootless mode. (-rootless) The X root window is hidden from view, but top-level X windows are drawn. Note: This is typically used to work with local or remote X applications, integrated into your native Windows desktop, but controlled using the X window manager of your choice. Because the X root window is hidden in this mode, this is not particulaly useful with X window managers with which you need to interact with the root window (for example, clicking on the root window to get a menu listing programs you can launch) [1] , but is more useful with X window managers which work with a dock or panel window for selecting applications from. Also note that the X window manager has no knowledge of the stacking of Windows windows, and vice versa, so raising one X window above a Windows window raises all of the X windows, and raising one Windows window above an X window raises it above all of the X windows. Exactly as if all X windows were being drawn into a hidden Windows window :-) __________________________________________________________________ Command line parameters Cygwin/X, by default, runs in windowed mode with the largest window that will fit on your Windows desktop, using the best performing engine that is installed on your system, with clipboard integration enabled. You do not need to pass any parameters to X to use the default behavior. Up to date documentation of X options can be read with man XWin . __________________________________________________________________ XWinrc configuration file With the .XWinrc configuration file it is possible to: * Add items and submenus into the menu opened by right-clicking on the notification area icon. * In multiwindow mode: add items and submenus into the Windows window system menu (opened by clicking on the icon in the top-left of the Windows window frame) and override the window icon and window styles for Windows windows, by window name or window class name. Full documentation of the XWinrc file format and command can be read with man XWinrc . __________________________________________________________________ Chapter 4. Using Cygwin/X Starting Cygwin/X Described below are several methods of starting up the Cygwin/X X Server with a startup utility that optionally starts initial clients (for example, a terminal or a window manager) and performs X server configuration (for example, loading a keyboard modifier map). __________________________________________________________________ Starting Cygwin/X in multiwindow mode (startxwin) Use the custom XWin startup utility startxwin startxwin is included in the xinit package (installed by following the instructions in the Section called Installing Cygwin/X in Chapter 2), which starts the X server in multiwindow mode along with a single X terminal. Run startxwin by: * using the "XWin Server" shortcut under "Cygwin-X" on the Start Menu * Starting /usr/bin/startxwin in a Cygwin shell: $ startxwin Full documentation for startxwin can be read with man startxwin . Note that the special option -- is used to mark the end of client options and the beginning of server options, so, for example, if you wish to start the X server with the -noclipboard option, as described in the Section called Command line parameters in Chapter 3, use the following command: $ startxwin -- -noclipboard You may create a ~/.startxwinrc script to customize the client programs started, rather than a single xterm. Note: The MS-DOS batch file startxwin.bat and bash shell script startxwin.sh previously used to start the X server are no longer provided. Implemented as a script made it difficult to reliably wait until the the X server had started before starting any clients. Use startxwin instead. Note: It's not recommended to start startxwin from a MS-DOS shell or by double-clicking it in Windows Explorer. To do so means that XWin is not started from a login shell, and programs started from the notification area icon menu will not inherit the environment of a login shell. This may lead to unexpected behaviour, for example, if you have customizations to your login shell start-up scripts which set environment variables. Note: If you want to have a Start Menu shortcut which runs startxwin with custom options, you should use a copy of the Start Menu shortcut installed by xinit, so that your changes are not overwritten when the xinit package is updated. Note: startxwin is a specialized version of startx with a few differences appropriate to running in multiwindow mode, rather than windowed mode. * startxwin supplies the -multiwindow option to X * It uses a different script to start clients (~/.startxwinrc rather than ~/.xinitrc), because ~/.xinitrc will normally end by starting a window manager, which would be incorrect for ~/.startxwinrc (as it would discover the internal window manager is already running and exit immediately). * startxwin exits after ~/.startxwinrc has completed and leaves X running, whereas startx waits until ~/.xinitrc exits (which is usually waiting for the window manager started by it to exit) and then kills X. __________________________________________________________________ Starting Cygwin/X in windowed mode (startx) Use the standard X Window System startx command with its attendant ~/.xinitrc configuration file. Run startx in a Cygwin shell: $ startx Full documentation for startx can be read with man startx . Note that the special option -- is used to mark the end of client options and the beginning of server options, so, for example, if you wish to start the X server with the -emulate3buttons option, as described in the Section called Command line parameters in Chapter 3, use the following command: $ startx -- -emulate3buttons You may create a ~/.xinitrc from the template in /etc/X11/xinit/xinitrc and then customize ~/.xinitrc to start client programs and configure your X server. $ cp /etc/X11/xinit/xinitrc ~/.xinitrc [edit ~/.xinitrc as desired] Note: startx waits until ~/.xinitrc exits (which is often waiting for a window manager started by it to exit) and then kills X, so the last client started by should be started with exec and without &. Alternatively, if you just want to start a single client program (perhaps a window manager), you don't need to use a ~/.xinitrc, and can start the client directly from startx, e.g. $ startx /usr/bin/fvwm2 Note: The client name supplied to startx must begin with / or ., otherwise it is treated as options to the default xterm client. __________________________________________________________________ Other startup methods Advanced users may wish to start the X server by invoking XWin directly, for example, to start XDMCP sessions. __________________________________________________________________ Switching out of Cygwin/X When running in windowed mode, press Alt-Tab to switch from Cygwin/X to your Windows desktop or other running Windows applications. __________________________________________________________________ Stopping Cygwin/X When you are done using Cygwin/X, you can shutdown the X server by: * Selecting the "Exit..." option from the notification area icon menu * In Windowed mode: Press Alt-F4 to shutdown the X Server. This can be disabled using the -nowinkill option. * In Windowed mode: Close the X server window in the conventional ways, e.g. by clicking on the "X" button at the upper-right corner of the X screen window frame, or choosing "Close" from the control menu opened by left-clicking on the X logo icon at the upper-left corner of the X screen window frame. * Using the -unixkill option allows the Ctrl-Alt-Backspace key combination to shutdown the X Server. If clients are still connected to the X server, you will be prompted to confirm you wish to shutdown the X server. __________________________________________________________________ Window managers A window manager is required in order to decorate, move, resize, and perform other operations on individual X windows. Cygwin/X can work with window managers in several different ways: * Internal window manager for multiwindow mode. The internal window manager that creates a Windows window for each top-level X window is automatically started when using the -multiwindow command-line parameter to X. See the Section called Command line parameters in Chapter 3 for more information on the -multiwindow command-line parameter. * External local window managers (e.g. twm, mwm (part of the lesstif package), fvwm2, openbox, aewm++, WindowMaker). These local window managers must be installed on Cygwin and run locally. * Remote window managers started by logging into an XDMCP session. You can read more about XDMCP in the Section called Remote sessions via XDMCP. * Remote window manager launched through an ssh tunnel. This is not Cygwin/X-specific, so you should be able to find information about launching remote window managers from other sources. See the Section called Secure ssh for more information on using ssh. __________________________________________________________________ Windows Clipboard integration The X Window System uses its own clipboard system that is distinct from the clipboard system used by Windows. Copying and pasting text between these two clipboard systems requires a clipboard integration program that watches for updates to either clipboard and copies data between them when either one is updated. Cygwin/X has an internal clipboard integration program that is enabled by default. The clipboard integration monitors the X PRIMARY and CLIBPOARD selections for changes in ownership, and makes the contents of the most recent one to change available to paste from the Windows clipboard. It also monitors the contents of the Windows clipboard for changes, taking ownership of the PRIMARY and CLIPBOARD selections, and making the contents of the Windows clipboard available in them. Note: Some X clients, notably ones written in Tcl/Tk, do not re-assert ownership of the PRIMARY selection or update it's timestamp when it's contents change, which currently prevents the clipboard integration program from correctly noticing that the PRIMARY selection's contents have changed. See the Section called Command line parameters in Chapter 3 for more information on the -[no]clipboard command-line parameter. __________________________________________________________________ Shared memory support Shared memory is needed by the MIT-SHM and XFree86-BigFont extensions, which may provide better performance for local applications which use large images or fonts and are written to use those extensions. In Cygwin, XSI shared memory is provided by the cygserver Windows service. To install cygserver, install it using setup.exe and then run the cygserver-config script to install the service. Note: This note is applicable to Cygwin 1.5 only. Cygwin 1.7 automatically enables shared memory if the cygserver Windows service is running. Shared memory will only be used if the CYGWIN environment variable contains the server keyword. For example, starting X with CYGWIN=server X or setting the CYGWIN environment variable in the Windows control panel to contain server will enable shared memory support if the cygserver service is running. __________________________________________________________________ Displaying remote clients Displaying remote X clients with Cygwin/X is identical to displaying remote X clients with any other X Server. It is recommended that you use the secure method of tunnelling the X connection over ssh. Alternatively, you can use the host-based access control provided by the X server, connecting to the remote machine using telnet or rsh and directing clients to connect to the server by setting the DISPLAY environment variable. This method is insecure and not recommended. __________________________________________________________________ Secure ssh On your Windows machine: 1. Make sure you have the openssh package installed. 2. Launch Cygwin/X 3. Ensure the DISPLAY environment variable is set correctly. (This step is not neccessary if you are entering your commands into an X terminal, as DISPLAY must already be set in that case) $ export DISPLAY=:0.0 4. Run the ssh command to connect to the remote host: $ ssh -Y username@remote_hostname_or_ip_address 5. Enter your password when prompted by ssh. 6. Your ssh session should now show you a shell prompt for your remote machine. Note: The ssh server will automatically set the DISPLAY environment variable appropriately, typically to something like localhost:10.0, so clients will connect to a proxy X11 display on the remote host from which the X11 protocol will be forwarded over ssh to your X server. If your login scripts unconditionally set DISPLAY to something else, this will break X11 forwarding. 7. You can now launch remote X clients in your ssh session, for example: $ xterm & will launch an xterm running on your remote host that will display on your Cygwin/X screen. 8. Launch other remote clients in the same manner. I recommend starting the remote clients in the background, by appending & to the command name, so that you don't have to open several ssh sessions. Note: By default, the OpenSSH server does not allow forwarded X connections. This must be configured on the remote host by adding X11Forwarding yes to the sshd_config configuration file. The OpenSSH server must be restarted or SIGHUP'ed to re-read the configuration file after it is changed. Note: The OpenSSH server requires the xauth command to be available to forward X connections. Consequently, it must be installed on the remote host. __________________________________________________________________ Insecure telnet or rsh (Not recommended) An example of connecting remote clients using host-based authorization. On your Windows machine: 1. Make sure you have the inetutils package installed (for telnet) or rsh package (for rsh). 2. Launch Cygwin/X 3. In an X terminal, use the xhost command to allow the remote host access to make connections to your X server: $ xhost remote_hostname_or_ip_address 4. Run the telnet or rsh command to connect to the remote host: $ /usr/bin/telnet remote_hostname_or_ip_address or $ rsh remote_hostname_or_ip_address Note: Use the explicit path to ensure that Cygwin's telnet is run instead of Microsoft's telnet. Microsoft's telnet cannot read input or display output correctly when run from a Cygwin shell. 5. Login to your remote machine 6. Ensure the DISPLAY environment variable is set correctly in your remote session. $ export DISPLAY=windows_hostname_or_ip_address:0.0 7. You can now launch remote X clients in your ssh session, for example: $ xterm & will launch an xterm running on your remote host that will display on your Cygwin/X screen. 8. Launch other remote clients in the same manner. I recommend starting the remote clients in the background, by appending & to the command name, so that you don't have to open several telnet or rsh sessions. Note: This is insecure because (1) when you log in, your username and password may be transmitted in clear across the network between you and the remote host (2) the X protocol is transmitted in clear across the network between you and the remote host, and (3) you have allowed any user on the remote host to connect to your X server and monitor your X session. For these reasons, use ssh forwarding, if at all possible. __________________________________________________________________ Remote sessions via XDMCP Cygwin/X can be used login to one or several remote sessions using XDMCP (X Display Manager Control Protocol). Start Cygwin/X with a command similar to the following to login to a single remote session using XDMCP: X -query remote_hostname_or_ip_address You may login to several remote sesstions with a single or multiple hosts using XDMCP. Each session will need a separate display number, specified by the :display_number parameter, such as :0. A display number is not the same as a screen number, as a single display can have multiple screens associated with it. Each display listens on a different network port number, so each display can connect to multiple machines. Start Cygwin/X with command lines similar to the following to login to several remote sessions using XDMCP: X :0 -query remote_hostname_or_ip_address_0 X :1 -query remote_hostname_or_ip_address_1 Note that the :display_number parameter is a general X Server parameter, not specific to Cygwin/X. Further documentation of the :display_number parameter can be found in the X Server manual page. XDMCP is a complex system that is not specific to Cygwin/X; further discussion of XDMCP is beyond the scope of this document. You may wish to read the Linux XDMCP HOWTO or the X Server XDMCP Options for more information. Note: For security reasons, XDMCP is not enabled by default on most modern UNIX distributions. You will have to enable remote logins to your X Display Manager (xdm, kdm, gdm, etc.). See the configuration documentation for your X Display Manager and/or UNIX distribution. The Cygwin/X FAQ section on XDMCP may also be helpful. Note: XDMCP suffers from some of the same security problems noted in the previous section, but unfortunately cannot be tunnelled over ssh due to it's use of UDP. A similar effect can be achieved with a command like ssh -Y remote_hostname_or_ip_address_1 Xnest :1 -query localhost __________________________________________________________________ Hardware Accelerated OpenGL (AIGLX) Note: This is feature is still under active development and should be considered beta quality, but should be working well enough to be useful. Please report success or failure with specific OpenGL applications to the cygwin-xfree mailing list. Cygwin/X supports hardware accelerated OpenGL rendering in the X server using the native Windows OpenGL (WGL) interface. Use the command line option -wgl to the X server to turn on the use of the native Windows OpenGL implementation. This option is only supported by multiwindow mode currently. If you don't use this option, the X server will use software rendering. For remote clients, Mesa's libGL prefers to use client-side rendering and transfer the image to the server using xlib. To force indirect rendering (which takes place on the server), you must do export LIBGL_ALWAYS_INDIRECT=1 before starting the client application. There's a performance trade-off between rendering performance and network latency, so you should try both direct and indirect rendering and see which performs best in your specific circumstances. Generally, accelerated indirect rendering should be more performant for clients which render complex scenes. For local clients, indirect rendering is the default, so no special steps are needed. If you have set things up successfully, glxinfo | grep OpenGL should output something mentioning your graphics card vendor. If it mentions Mesa, you still have software rendering Please ensure you are using the latest display drivers for your graphics hardware before reporting any visual issues with WGL. Known issues: * OpenGL windows with static contents aren't re-drawn when occluded by a native Window and then exposed. Workaround: force the window to redraw, e.g. by resizing it. * When an OpenGL window is behind a native application window which uses layered windows for translucency, the OpenGL rendering is drawn over the top, flickering. __________________________________________________________________ Input internationalization Compose key ('Multi_key') The compose key is a dead key which introduces a multi-key sequence to generate a character. You can configure the compose key by using setxkbmap e.g. setxkbmap -option compose:rctrl or starting the X server with the -xkboption option, e.g. X -xkboption compose:ralt. The possibilities for the compose key, e.g. ralt, lwin, rwin, menu, lctrl, rctrl, caps, etc. are listed in the xkeyboard-config(7) man page. Alternatively, the option lv3:ralt_switch_multikey configures Right Alt as 3rd-level shift, Shift + Right Alt [2] as Compose. Note that this option is on by default in the gb layout. The standard compose key sequences available are determined by the locale. Refer to the compose key sequence charts for the available compose key sequences for each locale. Note that most locales using a Microsoft codepage character set (e.g. with a LANG environment variable of the form LL_CC.CPnnn) are not currently recognized by Xlib. See the Compose(5) man page for more details on how the locale is mapped to a compose key sequence file and how to configure custom compose key sequences. __________________________________________________________________ Input Method Editors (IMEs) This section TBD. __________________________________________________________________ Terminal Server or Fast User Switching When multiple users may start X servers on same computer, each X server must have a unique display number. Instead of specifying a display number using the :display_number option, such as :0, starting the X server with the -displayfd option, locates an unused display number and writes it to the specified file descriptor. startx, xinit and startxwin notice this option, and transparently use it to determine the display number for any clients they start, and then pass on the display number to the specified file descriptor. Note: It may be necessary to also use the -engine 1 option (GDI drawing) for the X server windows to draw correctly when connecting to a Terminal Server using RDP, depending on the Windows version and/or graphics driver in use. Note: Automatically communicating the allocated display number to all future X clients started by the user who started the X server is left as an exercise for the reader. __________________________________________________________________ Appendix A. GNU Free Documentation License Version 1.1, March 2000 Copyright (C) 2000 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. __________________________________________________________________ 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software. We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference. __________________________________________________________________ 1. APPLICABILITY AND DEFINITIONS This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language. A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (For example, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them. The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, whose contents can be viewed and edited directly and straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent. A copy that is not "Transparent" is called "Opaque". Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML designed for human modification. Opaque formats include PostScript, PDF, proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML produced by some word processors for output purposes only. The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text. __________________________________________________________________ 2. VERBATIM COPYING You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies. __________________________________________________________________ 3. COPYING IN QUANTITY If you publish printed copies of the Document numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages. If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a publicly-accessible computer-network location containing a complete Transparent copy of the Document, free of added material, which the general network-using public has access to download anonymously at no charge using public-standard network protocols. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public. It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document. __________________________________________________________________ 4. MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version: A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission. B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has less than five). C. State on the Title page the name of the publisher of the Modified Version, as the publisher. D. Preserve all the copyright notices of the Document. E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices. F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below. G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice. H. Include an unaltered copy of this License. I. Preserve the section entitled "History", and its title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission. K. 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If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. __________________________________________________________________ How to use this License for your documents To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: Copyright (c) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. A copy of the license is included in the section entitled "GNU Free Documentation License". If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which ones are invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise for Back-Cover Texts. If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software. __________________________________________________________________ Colophon This document was produced from DocBook source XML using OpenJade and the DocBook DSSSL Stylesheets. The production process for this instance of this document was started at 2013-04-03 19:03 . Notes [1] Although this can be worked around, to some extent, by using a utility like xroot , which provides a clickable area of root window. [2] pressing the keys in that order. Right Alt + Shift is 4th-level shift.