Firefox version 78 is the last supported Firefox version for Mac users of OS X 10.9 Mavericks, OS X 10.10 Yosemite and OS X 10.11 El Capitan. These users will be moved to the Firefox Extended Support Release (ESR) channel by an application update. This will provide security updates until the next ESR update in July 2021, after which the affected users will no longer receive security updates.

While Apple does not have a public policy governing security updates for older OS X releases, their ongoing practice has been to support the most recent three releases. The last security update applicable to OS X 10.11 was made available in July 2018. Unsupported operating systems do not receive security updates, have known exploits and can be dangerous to use, which makes it difficult to maintain Firefox on those versions.

Up until July 2021, we will be updating affected users with critical security updates through the Firefox ESR channel to help retain the best possible security. After this, no security updates will be provided.

If you want to keep your Firefox version up to date, you will need to upgrade your operating system to macOS 10.12 or higher. Older versions that are not supported by Apple are unreliable and unsafe to use, which also makes it difficult to maintain Firefox on those versions.

Mac OS 10.14, Mac OS 10.13, Mac OS 10.12, Mac OS 10.11, Mac OS 10.10, Mac OS 10.9, Mac OS 10.8, Mac OS 10.7, Mac OS 10.6 Download File Logitech G13 Manual Download. How to upgrade from Mac OS x 10.9.5 to 10.10 (required for a new invoicing programme). For whatever reason, this iMac won't accept MacOS High Sierra, even though this shows up as freely available under Software Update. Those are either Mavericks Security Updates, or the Combo Updates that take the user from 10.9 to 10.9.5. The 'Install OS X Mavericks' should be on the order of 5 or 6GB in size (I do not have the exact size at the moment, but 1.5GB is way too small).

As of the posting of this tip, the Mac OS 9 downloads on Apple's support site are not fully available.

This tip of a method of obtaining the downloads was suggested by sdfox7. Special thanks to them for decoding

Mac Os 10.9 Manual Download

how to discover old downloads.

Locate the support.apple.com website for the download. In the case of most of the system downloads for Mac OS 9, there is this link:

and

In event the link doesn't work, go to http://web.archive.org/ to find it. For this link, the example site is:

If you are looking for the 9.2.2 download, the direct link from that page is

Clicking through

First on the page you will find North American English, 9.2.2, 21.3MB.

When you right click, or control-mouse button the download link and select copy link, you obtain:

Edit this link to reveal just the file name and not the path going to it and paste it in your favorite search engine. In this case, the file name is:

Mac_OS_9.2.2_Update.smi.bin

Searching you'll find that this link has that download.

As it happens, the website:

Mac Os 10.9 Manual Software

has the download links for all the Mac OS 9 updates and others.

You can use a similar method for many other downloads of older software.

As I also found out, .bin files even Mac OS X 10.9 understands. .smi files Disk utility won't open in Mac OS X 10.9, but it will convert to .dmg files.

Mac Os 10.9 Manual User

If you copy the contents to a USB Flash drive of the same name as the dmg file (without the suffix), it can hold the installer in question and connect older Mac OS 9 machines to run the installer from. Just make sure the USB drive is formatted HFS+ no journaling, or FAT16 and under 4GB in size.

The other thing to note, is that no Mac running Mac OS X 10.3 or higher supports the old style floppy disks of under 1.4 MB. The beige PowerMacs were the last that supported the 800k floppies with the single notch on the the corner. If you have floppies with two notches on either corner of the label, then they are 1.4 MB.

1.4 MB floppy looks like:

400k and 800k floppy look like:

Note how the 800k only has one notch for the write protect tab, and no other opening on the other corner.

The thread I learned about this method isLinks for Mac OS 9 Downloads are faulty!

Other older knowledgebase links can be found by this tip's methods:

Mac Os 10.9 Mavericks

Mac Os 10.9 Manual Iso

Some of the articles linked to for these updates may refer to the old knowledgebase format which may yield links you can convert with archive.org,

as described below:

Mac Os 10.9 Mavericks Free Download

Note: the ii.net mirror that used to be linked to no longer exists.