Unix & Windows
A significant new feature automatically optimizes the choice of encoding and pixel format based on an estimate of line speed. In most cases now the viewer will adapt to slow and fast links without needing extra command-line options. This is particularly useful if the desktop is viewed in the office over a good LAN connection, then later at home over a slow link. On connection, the algorithm assumes a slow link and uses 8-bit color and ZRLE. If the network seems fast, we switch to full-color. If the network seems really fast, we also switch to hextile rather than ZRLE. If server and viewer are on the same machine, we use raw.
Another significant development is a new encoding for slow links, ZRLE. This offer comparable compression to tight encoding, but better in some cases and much simpler in concept and implementation. It is a combination of the run length encoding scheme with tiling, palettisation and ZLIB compression.
HTTP server is more standards compliant.
Windows server
Improved reliability under certain network conditions. The capture of changes to the display and dispatch of changes to clients are now decoupled making the server more robust when dealing with slow clients. (Used to show up under Win9x in particular)
Improved multiple client behaviour
WinVNC now behaves better when multiple clients are connected and when one client stalls or is on a slow network connection.
Connection Management
Clients are no longer disconnected when the pixel format changes. They will be disconnected if the display size changes.
Security
WinVNC can be configured to logoff the current user when all clients have disconnected. Under Win2K and above, it can also be configured to lock the workstation on disconnect. Both options can be configured through the properties dialog. Logging code has been modified to avoid potential buffer overlow exploits.
The remove wallpaper option will now correctly restore the desktop wallpaper of the current user when the client disconnects. The option can be configured through the properties dialog. Keymapping improved, eg handling of circumflex character etc. Numerous smaller bug fixes, and code tidying. More lightweight InnoSetup installer rather than previous InstallShield.
Windows viewer
Mapping of the keypad "Enter" key fixed. "Empty password" bug on authentication cancel fixed. Fixed unhandled exception bug when a server connects and disconnects quickly.
Unix
Manual pages for all commands
vncconnect
vncserver
Xvnc
vncpasswd
vncviewer
Several fixes for AIX, HPUX, etc
HTTP daemon denial-of-service vulnerability fixed, also fixes to work better with more browsers. X viewer can now switch 8-bit / full colour mode on the fly via the popup window. vncserver now uses depth 16 by default, and the default pixel format for depths 16 and 24 are now more sensible. Better challenge generation in authentication code. vncconnect now has a "-away" option to cause a disconnect. Improved build system based on autoconf.