Mozilla maintains an archive of nearly every version ever released. You can find the specific files for 3.6 through these official channels:

Sometimes, you just want to see what the internet looked like before responsive design or HTTPS became mandatory.

If your goal is general browsing, use a modern supported browser instead.

Downloading an old version of Mozilla Firefox 3.6 can be done through the Mozilla FTP archive or Firefox Archive. However, users should be aware of the potential security risks, lack of support, and compatibility issues associated with using an outdated browser. It is recommended to use a modern and updated browser to ensure a safe and optimal browsing experience.