macOS 10.15 Catalina

macOS Catalina — released in October 2019 — marked some major changes to the operating system. Not a single 32-bit app will run on Catalina, as Apple has made everything 64-bit in the OS and its frameworks. It’s the end of the road of older Mac applications, including every one using the Carbon APIs. macOS 10.15 is also the first to support Catalyst, which allows developers to port their iPad apps to the Mac. Also new is SwiftUI, which is Apple’s long-term play to let developers write one app to run across all of Apple’s software platforms.

After 18 years, the kingdom of iTunes has fallen. Three new apps (Music, Podcasts and TV) are here to take over the old title’s various duties.

You can check out my Catalina review here.

Like Mojave before it, Catalina support both Light and Dark Modes, but Apple has added an “Auto” appearance that changes the desktop wallpaper, mode and Night Shift white balance as the day progresses. There are actually eight variants of the default wallpaper, which you can see here.

Sponsored by Rogue Amoeba

Rogue Amoeba is proud to continue our sponsorship of the 512 Pixels macOS Screenshot Library. For over two decades, we’ve been making amazing macOS audio software. Check our very own historic screenshot archive to confirm it!

From recording anything with Audio Hijack to getting superior control over all the sound on your Mac with SoundSource, we have tools for all your audio needs. Visit to learn about all our great utilities.

Appearance & Accent Combinations

Light Mode

Dark Mode

← Downgrade to macOS 10.14 Mojave

View all entries in the Aqua Screenshot Library or check out OS X’s default wallpapers, updated for 5K Retina displays.

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