Download of MX4 2.2 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
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 software for Mac OS X is a product of MOTU Inc. The most popular version among the program users is 2.2. The application is included in Audio & Video Tools.
From the developer:
Meet the new instrument plug-in powerhouse for your studio. Inspired by legendary subtractive synthesizers, MX4 combines several core synthesis techniques in a unified, hybrid synthesis engine that delivers fresh and vintage sounds alike.
As you explore its many banks and hundreds of presets, you'll soon rely on MX4 as your "go-to" instrument. Fat basses, nasty leads, analog pads, vintage electronica
You may want to check out more Mac applications, such as MOTU MX4, which might be similar to MX4.