PRE-DOWNLOAD WORD OF WARNING, READ!
Before you continue to the download page you should read the following blog pages, they might answer a lot of your questions before they even form.
Automatic Alpha Masking
Movement Controls
Spotlights
User Interface Tour
Complexity
FAQ
You may want to visit the Discord Channel too!
You might want to read the Privacy Policy too if you are into that stuff.
Should you get an error message on startup and you use Windows 10/11 you'll need to head over to the Microsoft website and download the latest Visual C++ Redistributable 2013 and Visual C++ Redistributable 2015/2017/2019/2022 X64 package, the Viewer requires it, comes with its DLL files but Windows 10 with all the latest updates requires new ones.
DO NOT download the Viewer anywhere else other than from these links! The Viewer is ONLY available from here and only for Windows.
This software is not provided or supported by Linden Lab, the makers of Second Life.