Downloading REDAlert 21.0 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The software belongs to System Tools. We recommend checking the downloaded files with any free antivirus. The actual developer of this free Mac application is RED.com, Inc.
From the developer:
RED Alert is an application designed specifically for RED Rocket.
Red Alert allows you to read REDCODE RAW files, perform white balance, contrast and one light color correction then export DPX, TIFF or QuickTime reference movies. Includes Automator Actions and prior versions of REDLine.
Red Alert supports all RED ONE camera firmware builds up through Build 21.
You may want to check out more software for Mac, such as Rhythm Red Alert, which might be related to REDAlert.