I'm using an old iMac G3, running Mac OS 10.3.9 Panther, for research purposes. My concern is not security - I don't put sensitive information on this machine, nor do I mind if the integrity of the Operating System is compromised. I just want to be able to connect to the internet for benchmarking purposes. I am aware that the specs of this machine are too low to run most websites.
As you're probably aware, the SSL security protocols on this version of Mac OS X are out of date enough to prevent me from visiting anything aside from Google.
One step I've taken care of is following the directions from How do I update my root certificates on an older version of Mac OS (e.g. El Capitan)? :
Some operating systems hold onto the expired R3 > DST Root CA X3 chain even if your server is no longer using it. Try a restart of the affected client device.
For older macOS not updated by Apple:
Download the ISRG Root X1 certificate file from http://x1.i.lencr.org/ Open the Keychain Access app and drag that file into the System folder of that app. Find the ISRG Root X1 certificate in System and double click on it, open the Trust menu and change "Use System Defaults" to "Always Trust", then close that and enter your password to confirm the change (if prompted).
I seem to be able to connect to Google via HTTPS, which is a step up, but sites like Wikipedia still prevent me from accessing them for security reasons. What else could I try doing in order to get this computer on the internet (for better or worse)?