Virtual Network Computing (VNC) is a remote display system that allows you to effortlessly view and interact with a virtual desktop environment on another computer within the same network.

With VNC, you can easily run graphical applications on a remote machine and transmit the display output to your local machine. VNC is compatible with various operating systems and architectures, serving as both a server and a client.

1- TigerVNC

TigerVNC is a high-speed version of VNC based on the RealVNC 4 and X.org code bases. It was developed as a next-generation enhancement for TightVNC on Unix and Linux platforms, with the aim of providing improved performance and functionality.

In early 2009, TigerVNC split from its parent project to allow TightVNC to concentrate on Windows platforms, while TigerVNC continued its development for Unix and Linux.

One of the notable features of TigerVNC is its support for a variant of Tight encoding, which utilizes the libjpeg-turbo JPEG codec.

This implementation significantly accelerates the encoding and decoding process, resulting in faster and more efficient data transfer during VNC sessions. By leveraging this optimized encoding technique, TigerVNC is able to deliver a smoother and more responsive remote desktop experience.

This software is distributed under the GNU General Public License as published by the Free Software Foundation. 

TigerVNC
GitHub - TigerVNC/tigervnc: High performance, multi-platform VNC client and server
High performance, multi-platform VNC client and server - GitHub - TigerVNC/tigervnc: High performance, multi-platform VNC client and server

2- SmartPuTTY

SmartPutty is a user-friendly and powerful terminal emulation application for Windows. It allows secure remote system access, seamless file transfer, and native support for VNC, making it valuable for computing professionals who need to manage remote resources and access graphical applications.

SmartPutty: Putty for Serious Users With Multiple Tabs Support
SmartPutty is an innovative and user-friendly free open-source application specifically designed for the Windows platform. It provides a wide range of powerful and reliable terminal emulation capabilities that are essential for computing professionals. This exceptional app greatly contributes to enh…

3- EfonVNC

The EfonVNC project is a powerful open-source Windows CE Toolset that offers a wide range of remote control tools based on RealVNC, along with other highly useful system helper utilities.

It is specifically designed to cater to the needs of developers and users who are working with Microsoft Windows CE 5.0 or newer versions.

EfonVNC
Download EfonVNC for free. VNC Server For WinCE. The EfonVNC project is an open source Windows CE Toolset. It contain remote control tools, which is based on RealVNC, And other system helper utils.

4- noVNC

noVNC is both an HTML VNC client JavaScript library and an application built on top of that library. noVNC runs well in any modern browser including mobile browsers (iOS and Android).

Features

  • Supports all modern browsers including mobile (iOS, Android)
  • Supported authentication methods: none, classical VNC, RealVNC's RSA-AES, Tight, VeNCrypt Plain, XVP, Apple's Diffie-Hellman, UltraVNC's MSLogonII
  • Supported VNC encodings: raw, copyrect, rre, hextile, tight, tightPNG, ZRLE, JPEG
  • Supports scaling, clipping and resizing the desktop
  • Local cursor rendering
  • Clipboard copy/paste with full Unicode support
  • Translations
  • Touch gestures for emulating common mouse actions
  • Licensed mainly under the MPL 2.0.

GitHub - novnc/noVNC: VNC client web application
VNC client web application. Contribute to novnc/noVNC development by creating an account on GitHub.

5- SpiritVNC - FLTK

SpiritVNC - FLTK  is an FLTK-based multi-view VNC client for Unix-like systems, including Linux, macOS, and FreeBSD.

SpiritVNC features VNC-through-SSH, reverse (listening) VNC connections and timed scanning of connected viewers.

GitHub - willbprog127/spiritvnc-fltk: A multi-view VNC viewer for Linux, FreeBSD, macOS and others
A multi-view VNC viewer for Linux, FreeBSD, macOS and others - GitHub - willbprog127/spiritvnc-fltk: A multi-view VNC viewer for Linux, FreeBSD, macOS and others

6- Docker Guacamole

Docker Guacamole is an open-source Docker Container for Apache Guacamole, a client-less remote desktop gateway.

It supports standard protocols like VNC, RDP, and SSH over HTML5.

GitHub - lusky3/docker-guacamole: A self-contained guacamole docker container for x64 and ARM. Remotely connect over SSH, RDP or VNC using HTML5.
A self-contained guacamole docker container for x64 and ARM. Remotely connect over SSH, RDP or VNC using HTML5. - GitHub - lusky3/docker-guacamole: A self-contained guacamole docker container for x…

7- Remmina

Remmina is a remote-desktop client written in GTK, to use other desktops remotely, from a tiny screen or large monitors.

Remmina supports multiple network protocols in an integrated and consistent user interface. The protocols currently supported are: X2Go, RDP (Remote Desktop Protocol), VNC (Virtual Network Computing), and SSH (Secure Shell / Open SSH).

Remmina | Flathub
Remote Desktop Client

8- RoyalVNC

RoyalVNC is a modern, high performance implementation of the VNC/RFB protocol written in Swift. The SDK (RoyalVNCKit) is compatible with Swift and Objective-C on macOS, iOS and iPadOS.

It has no external dependencies but includes some free (public domain) third party code from the libtommath and D3DES libraries (see Credits).

Security Types (Authentication Methods)

  • No Authentication
  • VNC Password
  • Apple Remote Desktop
  • UltraVNC MS-Logon II
GitHub - royalapplications/royalvnc: A modern, high performance implementation of the VNC/RFB protocol written in Swift.
A modern, high performance implementation of the VNC/RFB protocol written in Swift. - GitHub - royalapplications/royalvnc: A modern, high performance implementation of the VNC/RFB protocol written…

9- UltraVNC

UltraVNC is a powerful, easy to use and free - remote pc access pieces of software - that can display the screen of another computer (via internet or network) on your own screen.

The program allows you to use your mouse and keyboard to control the other PC remotely. It means that you can work on a remote computer, as if you were sitting in front of it, right from your current location.

VNC, the Remote Frame Buffer protocol (RFB) allows a desktop to be viewed and controlled remotely over the Internet.

A VNC server must be run on the computer sharing the desktop, a VNC client must be run on the computer that will access the shared desktop.

Home - UltraVNC VNC OFFICIAL SITE, Remote Desktop Free Opensource
VNC remote desktop support software for remote PC control. Free. Anydesk , teamviewer alternative
GitHub - ultravnc/UltraVNC: UltraVNC Server, UltraVNC Viewer and UltraVNC SC | Official repository: https://github.com/ultravnc/UltraVNC
UltraVNC Server, UltraVNC Viewer and UltraVNC SC | Official repository: https://github.com/ultravnc/UltraVNC - GitHub - ultravnc/UltraVNC: UltraVNC Server, UltraVNC Viewer and UltraVNC SC | Officia…

10- MultiVNC

MultiVNC is a cross-platform Multicast-enabled VNC viewer based on LibVNCClient.

The desktop version uses wxWidgets and runs on Unix, Mac OS X and Windows. There is also an Android version.

Features (Android)

  • Support for most VNC encodings including Tight.
  • TLS support, i.e. AnonTLS and VeNCrypt.
  • Support for SSH-Tunnelling with password- and privkey-based authentication.
  • UltraVNC Repeater support.
  • Discovery of VNC servers advertising themselves via ZeroConf.
  • Bookmarking of connections.
  • Import and export of saved connections.
  • Virtual mouse button controls with haptic feedback.
  • Two-finger swipe gesture recognition.
  • A superfast touchpad mode for local use.
  • Hardware-accelerated OpenGL drawing and zooming.
  • Supports server framebuffer resize.
  • Copy&paste to and from Android.

Features (Desktop)

  • Support for most encodings including Tight.
  • TLS support, i.e. AnonTLS and VeNCrypt.
  • Discovery of VNC servers advertising themselves via ZeroConf.
  • Bookmarking of connections.
  • Supports server framebuffer resize.
  • Several connections with one viewer using tabs.
  • Listen mode (Reverse VNC). Via tabs, it's possible to listen for and serve multiple incoming connections.
  • Record and replay of user input macros.
  • Under X11, seamless control of the remote side by moving pointer over the (default upper) screen edge. Borrows heavily from x2vnc by Fredrik Hübinette [email protected], which in turn was based on ideas from x2x and code from vncviewer.
  • Simple, loggable statistics.
  • MulticastVNC ;-)
GitHub - bk138/multivnc: MultiVNC is a cross-platform Multicast-enabled VNC viewer based on LibVNCClient. The desktop version runs on Unix, Mac OS X and Windows. There also is an Android version.
MultiVNC is a cross-platform Multicast-enabled VNC viewer based on LibVNCClient. The desktop version runs on Unix, Mac OS X and Windows. There also is an Android version. - GitHub - bk138/multivnc:…

11- VNSee

VNC client for the reMarkable tablet allowing you to use the device as a second screen.

VNSee brings both worlds together by allowing the tablet to connect to a remote VNC server, show the remote screen on its E-Ink display and interact with it through the pen digitizer and touchscreen.

This can effectively turn the tablet into a second screen for your computer.

Applications include reading web-based content, typing documents, drawing, or previewing LaTeX documents as you compose them.

The software is released and licensed under the GPL v3.

GitHub - matteodelabre/vnsee: VNC client for the reMarkable tablet allowing you to use the device as a second screen
VNC client for the reMarkable tablet allowing you to use the device as a second screen - GitHub - matteodelabre/vnsee: VNC client for the reMarkable tablet allowing you to use the device as a secon…

12- VNCViewer (macOS)

VNCViewer is a native (Cocoa-based) open-source free VNC client for macOS.

VNCViewer
Download VNCViewer for free. VNCViewer is a Cocoa-based VNC client for Mac OS X.

13- Remote Viewer

Remote Viewer provides a graphical viewer for the guest OS display. At this time it supports guest OS using the VNC or SPICE protocols.

Further protocols may be supported in the future as user demand dictates. The viewer can connect directly to both local and remotely hosted guest OS, optionally using SSL/TLS encryption.

Remote Viewer | Flathub
Remotely access virtual machines

14- Next Terminal

Next Terminal is an open-source Terminal app that provides access to RDP, SSH, VNC, TELNET, and other protocols without the need for plug-ins, just a browser. You can monitor and block active sessions and restrict certain commands for character protocols.

Next Terminal logs all online resources, connections, sessions, and security events in a structured audit log.

It is developed with Golang and has a lightweight design with a one-line command installation.

Features

  • Easy to use and safe open source interactive audit system
  • Free open source
  • Multiprotocol support
  • Real time monitoring
  • Post audit
  • We use one of the most secure encryption algorithms
Next Terminal
Download Next Terminal for free. Open source interactive audit system that supports RDP, SSH, VNC, The Next Terminal open-source project has gained nearly 3,000 Stars on GitHub and has a large number of users, so you can absolutely trust the stability of Next Terminal. You can access RDP, SSH, VNC,…
Next Terminal: Web-based Multipurpose Terminal for Developers and DevOps
Next Terminal, an impressive open-source project, has gained considerable popularity among developers. With almost 3,000 stars on GitHub and a large user base, it is evident that Next Terminal is highly regarded for its exceptional stability and reliability. Users can confidently rely on Next Termi…

15- VNC-Client library for C#

This project provides a very performant, fully managed C#-Library that implements the RFB protocol for easy integration of VNC-Client features into own applications.

It's also cross-platform and runs everywhere .NET Core (or .NET 5 and so on.) runs.

Features

  • Highly configurable and extensible structure
  • Flexible transport layer selection (TCP by default)
  • Automatic reconnects with configurable behavior
  • Supported security types: NoneVNC Authentication
  • Supported message types: SetEncodingsFramebufferUpdateRequestFramebufferUpdateServerCutTextSetDesktopSizeServerFenceClientFenceEnableContinuousUpdatesEndOfContinuousUpdatesPointerEventKeyEventBell
  • Supported frame encoding types: RawCopyRectzLibZRLETight
  • Supported pseudo encoding types: FenceContinuousUpdatesLastRectJPEG Quality LevelJPEG Fine-Grained Quality LevelJPEG Subsampling LevelDesktopSizeExtendedDesktopSize
  • Allows smooth image transmission or even video streaming (over sufficiently fast connections) thanks to a very efficient implementation
  • Allows changing the JPEG quality levels
  • Supports all kinds of color depths up to - theoretically - even 32bit HDR (untested, please tell me if you know a server to test this with 😀)
  • Supports continuous framebuffer updates and advanced flow control
  • Supports keyboard and pointer input with horizontal and vertical scrolling
  • Supports clipboard sharing (currently only server to client, I'm open for PRs)
  • Full support for dynamic session resizing (server-side and client-side) with all the APIs exposed for multi-monitor scenarios
  • Option for visualizing received rectangles (useful for debugging or analytic purposes)
  • The render target can be detached or replaced and any time and the client can even run in a fully headless mode without any rendering
  • Exposes many useful connection details in an observable manner (INotifyPropertyChanged)
  • Very detailed log output for debugging/analytic purposes
VNC-Client Library for C#
High-performance cross-platform VNC-Client library for C#
GitHub - MarcusWichelmann/MarcusW.VncClient: High-performance cross-platform VNC-Client library for C#
High-performance cross-platform VNC-Client library for C# - GitHub - MarcusWichelmann/MarcusW.VncClient: High-performance cross-platform VNC-Client library for C#