The 5.40 version of GarminUpdater for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. GarminUpdater for Mac lies within System Tools, more precisely Device Assistants. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free Mac application is a product of Garmin Ltd. or its subsidiaries.
From the developer:
GarminUpdater is a free application that lets you check for and install software updates without using an Internet web browser. The app updates most products, excluding Palm and Pocket PC devices, fixed-mount marine devices, chartplotters, fishfinders and certain discontinued devices.
You may want to check out more software for Mac, such as Macfilink, Missing Sync for Palm Pre or FourEyes3D, which might be related to GarminUpdater.