If you find a viewer which can connect to OpenSimulator then please add it to the bottom of the appropriate list.

Compatibility issues

Since OpenSimulator and viewers development is done by diferent teams with diferent timing and even goals, compatibility can not be assured.
To connect to a older version of OpenSimulator, you may need to use a older version of your favority viewer. Consult your grid team, or the viewer team
This may also limit Hypergrid capability.

Viewers

• Cool VL Viewer - the oldest of all actively maintained Third Party Viewers (former name: Cool SL Viewer).
• FireStorm Viewer - v3 based TPV, the successor to Phoenix. The most widely used viewer on Second Life.
• Kokua - v3 based successor to Imprudence.
• Radegast Metaverse Client - Radegast-ng is Light client, evolution of Radagast from libopenmetaverae project.
• Singularity - A Snowglobe-based viewer with many current features backported.
• Dayturn - A OpenSim compatible viewer derived from Kokua.
• Scenegate - A viewer with a focus on accessibility, and onboarding. With a simplified UI more suitable to just visit worlds, rather than building (but the full UI is still accessible). Derived from Alchemy Viewer

Beta Viewers

Singularity Nightly Builds http://www.singularityviewer.org/kb/nightly-builds

Dayturn-windows https://bitbucket.org/dayturn/dayturn-windows/downloads/

Text-only Viewers

These are lightweight viewers, which either do not offer a graphical component or where the graphical component is not used by deault. The function of these viewers however is to connect to a grid, chat, manage inventory, etc. Useful on systems with low specifications or for bringing an alt online without having your main avatar log out, or to quickly take care of messages, inventory, etc.

• JOpenMetaverse Purely Java based OpenSim client core library. Windows, MacOS,, Linux and Android Compatible. Please see jopenmetaverse introduction
• METAbolt - METAbolt is a non-graphical (text based) viewer. It's light weight and cross grid, which means it will work in Second Life™ as well as other grids that are based on OpenSIM. The viewer is Open Source so it's free. Currently METAbolt is only available for Windows platforms.
• Mobile Grid Client - A Second Life and OpenSim (Open Simulator) messaging client for your Android powered device (mobile phone, cell phone, tablet...).

Inactive Viewers

• 3Di viewer Rei - C# based Web-browser plugin OpenSimulator viewer. 3Di website gone but 3Di Rei viewer source is still available on Github
• Dolphin - C++ based viewer for Linux/Mac/Win. Abandoned in 2015. Dolphin 3 Source still available on Github.
• Hippo - C++ based viewer for Linux/Mac/Win. Abandoned in 2010.
• Idealist - C# Multi-platform 32 bit viewer intended to be OpenSimulator focused
• Imprudence - Innovative C++ viewer with a focus on OpenSimulator. Imprudence Viewer source is still available on Github
• LookingGlass - C#/Ogre based Viewer. Development Ended in 2011. LookingGlass Viewer source is still available on Github
• Meerkat - Viewer for Linux/Mac/Win in C++. Meerkat source available on Github. Meerkat binaries available via Google Code Archive.
• OpenViewer - C#/Ogre based, BSD licensed viewer written as a companion to OpenSimulator. ca 2007/2008. Website went dark in 2009.
• RealXtend - Fork of the v1.23 Linden Client that has specialized features (not fully supported.)
• Xenki - XABP-based OpenSimulator viewer for the IE web browser.