Guacamole 0.9.1 (Legacy)

The release below is from prior to Guacamole's acceptance into the Apache Incubator. It is not an Apache Software Foundation release, and is licensed under the MIT license. The latest release of Apache Guacamole is 1.5.5.

The 0.9.1 release of Guacamole improves performance of both VNC and RDP, while also greatly enhancing the user interface. A new menu has been added to the client screen which allows direct access to input settings. Telnet support has also been added, using the same terminal emulation used by the existing SSH support.


Updates received via VNC and RDP are now automatically combined with each other when doing so appears to be more efficient. This has the effect of reducing network and processing load on the client and server, resulting in a more responsive experience.

The manner in which individual frames are queued up and rendered has also been improved, decreasing the amount of time required to render each frame, and guaranteeing that the entire frame renders atomically, rather than in individual pieces. Atomic frames are more efficient and feel snappier.

Improved interface and mobile support

The Guacamole interface has been vastly improved. The clipboard and settings sections which were on the connection list screen have been moved into a menu within the client screen. When using any connection, you can press Ctrl+Alt+Shift to show this menu and access the clipboard, zoom settings, and various input methods. On mobile or touch devices, you can show this menu by swiping right from the left side of the screen.

By popular demand, the default mouse emulation mode for touch devices is now “absolute”. This means you tap to click at the location that you wish to click. You can switch back to the old relative emulation (touchpad) by selecting this option within the menu.

On mobile or touch devices, typing is more convenient thanks to the new “text input” mode (a choice within the new menu), and you can pan or zoom the screen by dragging your finger or pinching.


Leveraging the terminal emulation used by Guacamole’s SSH support, we now have support for Telnet. Telnet support depends on libtelnet, and will be built along with the other protocols if you have libtelnet installed. It functions exactly like the existing SSH support, though the lack of authentication built into the Telnet protocol means that you currently cannot specify a username/password combination for Telnet connections.

MySQL fixes

The MySQL auth would occasionally report connections as in-use when they were actually free. This is now fixed. An issue which caused logins to initially fail when the MySQL connection had not recently been used is fixed as well.

Terminal rendering

SSH (and now Telnet) suffered from an issue where the cursor, and possibly text on the screen, would disappear when the browser window was resized. This is now fixed.

Clipboard fixes

Guacamole now supports Unicode clipboard data for RDP. Past releases lacked this support, and would result in mangled copy/paste results when the data contained Unicode characters.

Limitations added in a recent release resulted in a regression which prevented copy/paste of large blocks of text. We have now modified the manner in which clipboard data is transferred, and this limitation no longer applies.