What os should I update to?

Unless you have previously downloaded a newer OS, your only choices are to purchase Mountain Lion or install El Capitan. After installing El Capitan, you can consider Sierra.

Check that your computer is compatible with Mountain Lion/Mavericks/Yosemite/El Capitan.

To check the model number hold down the option/alt key, go to the Apple menu and select System Information.

iMac (Mid 2007 or newer) model number 7,1 or higher

El Capitan

Check to make sure your applications are compatible. PowerPC applications are no longer supported after 10.6.

Application Compatibility

Applications Compatibility (2)

El Capitan 10.11 Compatibility information

macOS Sierra 10.12: Compatible Apps

Also check to make sure there is a compatible driver for your printer.

Do a backup before installing, preferable 2 backups on 2 different drives.

How to get macOS Sierra

To check the model number hold down the option/alt key, go to the Apple menu and select System Information.

macOS 10.12 (Sierra) requires one of the following Macs:

iMac (Late 2009 or later) Model 10.1 and higher

I jumped from 10.7.5 to Sierra in one leap. All would have been OK were it not for the fact (TOTALLY unknown to us) that the RAM in our iMac had been removed and replaced with RAM from an earlier model, which is like putting the battery of a one litre car into a two litre engine......sloooow isn't the word. Weeks later we are waiting on replacement of same; which isn't filling my confidence in aftercare from Apple one bit.

If it weren't for the support community here, we would never have discovered our problem.

Cheers

Had to reply just in case someone else has this problem (though our retailer says it's a one-off........)

Firefox is still supported for OS X 10.6.8-10.8.5 here.

Mozilla Firefox ESR (Extended Security Release) web browser and it looks like Mozilla is extended its ESR web browser support for OS X 10.6.8-10.8.5 until mid 2018. Support was scheduled to end this month.

Download here.

https://www.mozilla.org/en-US/firefox/organizations/faq/

Ignore all of the entreprise/organisations/educational info.

Good Luck!

Actually, the latest version of Firefox for personal computers (52.0.2) cannot be loaded onto Apple products using OS X 10.6.8... to my knowledge, the last Firefox version for OSX 10.6.8 is Firefox version 48.0.2... and the message I see when I open the "About Firefox" tab states "You cannot perform further updates on this system"

Firefox latest system requirements are found here: https://www.mozilla.org/en-US/firefox/52.0.2/system-requirements/

Stephen

Use the ESR version!

https://www.mozilla.org/en-US/firefox/organizations/faq/

My wife and I and a whole slew of other that I have advised here are using the ESR version of Firefox on 10.6.8-10.8.5.

The ESR version is an older version of the more recent Firefox in Web Browser features ONLY!

The ESR version of Firefox is receiving ALL of the same security updates as the more current version of Firefox.

Ignore all the info about enterprise/organisations/education stuff.

This version is perfectly fine for OS X 10.6.8 through 10.8.5.

Current Firefox ESR version is 45.8.

The TenFourFox web browser for OS X 10.4.11 & 10.5.8 is based on the Mozilla Firefox ESR web browser!

Good Luck!

You have a viable, secure option for a web browser, now, if you wish to stay with OS X 10.6.8 Snow Leopard.

Moziila extended out support for the ESR web browser for another year.

So, if you were just going to update to regain a secure web browser, you have that option now just to install the ESR version of Firefox and remain/stick with OS X 10.6.8, if you wish.

Firefox ESR 45.8 is, currently, the latest secure version.

Good Luck on whatever you decide.