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X VNC History

The version and release numbers are explained on the main VNC history page. This page primarily concerns changes to the Unix and Java packages. The changes to the Windows packages are listed separately here

The important changes in each version are summarised here; see the source package for more details.

Want to get the latest version? Go to the Download Page.

Changes in version 3.3.3R2


  • New helper program for Xvnc, which causes it to make reverse connections to a listening VNC viewer. This is similar to WinVNC's "Add New Client" / -connect feature.


  • New option -inetd incorporating Andre Moreira's iXvnc functionality.
  • Fix to hextile encoding, thanks to Michael A. Fetterman - this may be the cause of the "0 bpp problem".
  • New connect out feature by using the vncconnect command.
  • Fix some non-ascii capitalisation issues, thanks to Vlad Harchev.
  • Fix bounding box calculation for arcs.
  • Other minor bug fixes.


  • Sets DISPLAY to use unix domain socket if possible (:dpynum rather than host:dpynum).
  • Option -kill should now work if you give it $DISPLAY as an argument.


  • Fix Xaw string copy bug, thanks to Tim Waugh - this fixes the problems with the password dialog with recent versions of linux

Java viewer

  • Improve keyboard handling for Latin-1 characters and ctrl-_.
  • Change constants so (hopefully) will compile with JDK 1.3

Release date: 26 October 2000

Changes in version 3.3.3R1


  • Xvnc now uses a "deferred update" mechanism which enhances performance in many cases. After any change to the framebuffer, Xvnc waits for a time (default 40ms) before sending an update to any waiting clients. This means that more changes tend to get coalesced together in a single update. The time can be changed with the -deferupdate option. Setting it to 0 results in the same behaviour as previous versions of Xvnc.
  • There are a couple of security enhancements. The -localhost option now causes Xvnc to only listen on the loopback interface. This means that it shouldn't be vulnerable to port scanning. Also a "too many tries" feature on authentication failure is now implemented. After five failed attempts, further attempts are delayed by an exponentially increasing amount, starting at ten seconds.


  • Uses SO_REUSEADDR when testing to see which ports are free.


  • When given -owncmap in full screen mode, tries to install the colormap. This works only when no window manager is running.
  • The popup window now always uses the default colormap.
  • The "backing store" attribute can now be set on the desktop window via the "backingStore" resource. It defaults to "Always", meaning the X server should keep the contents of the viewer window when it gets obscured by other windows.

Release date: 9 February 2000

Changes in version 3.3.3


    New options -alwaysshared, -nevershared, -dontdisconnect and -localhost.
    Fixed problem with 16-bit desktops on Solaris and other platforms.
    Default dpi now 75.
    Don't die on non-existent font directory at startup (common RedHat 6 problem).
    Copes with up to 5 pointer buttons.
    Fixed zero-area copy bug.
    Fixed occasional bug when multiple clients and one disconnects.


    Work around bug in perl 5.005_02 which caused bad display names such as "snoopy:".


    Fixed minor bugs.


    Completely new viewer based on Xt. Development has ceased on the old Xlib-based viewer.

Release date: 19 August 1999

Changes in version 3.3.2 R3


    Fixed an important memory leak.


    The vncserver script should cope better with different Perl versions.
    X cookies generated more securely.


    Uses shared memory on Linux.
    More secure clearing of password.

Release date: 14 December 1998

Changes in version 3.3.2 R2


    Cutting text inside Xvnc works to a remote viewer again.

    Resource leak fixed which limited total number of times Xvnc could be connected to.


    Warns of likely failure when starting a 16 bpp desktop on Solaris.

    No longer tries to find out the geometry, depth and pixel format of the current X display being used. This feature can be enabled if desired by uncommenting a line in the script.

Release date: 23 July 1998

Changes in version 3.3.2

The changes in 3.3.2 will have little effect on the normal user.  There should be a slight increase in speed in certain circumstances, but the majority of changes are 'under the hood'.  The X server is now based on XFree86 3.3.2.  This should make it easier to build on more platforms, and means that it is now based on X11R6.3 rather than X11R6. 

X vncviewer

  • -viewonly, -geometry, -wmdecoration options
  • Options for debugging servers: change -delay to -rawdelay, plus

  • -copyrectdelay, -region
  • Options allowed before or after host:dpynum argument
  • Handle changes to local X keyboard mapping
  • Rudimentary single bit-per-pixel support (thanks to Chris Hooper)

Xvnc server

  • Based on XFree86 3.3.2 distribution
  • Faster pixel-format translation routines
  • Improved HTTP server. Now performs substitution on any files ending in .vnc, so that default options to the VNC applet can be configured on the server side.
  • -economictranslate option to use less memory-hungry translation
  • Supports viewers requesting only a subregion of the screen.
  • Better log file messages with timestamps.

For comments, feedback, etc, please see the 'Keeping in touch' page.
Copyright 1999 - AT&T Laboratories Cambridge