Java (IntelliJ/AndroidStudio):

Kotlin (IntelliJ/AndroidStudio):

Python (PyCharm): TODO

WebStorm: TODO

Copy the *.icls file to the colors/ subdirectory of where your Preferences are stored:

See this link to find out the location based on the OS & JetBrains product.

For macOS, this is located at:
~/Library/Preferences/{PRODUCT}{VERSION}/colors/
e.g.:
~/Library/Preferences/IntelliJIdea2019.2/colors/ or ~/Library/Preferences/IdeaIC2018.2/colors/

The Themes work best with Material Theme UI. This color scheme goes well with the Atom One Dark UI Theme Setting. To switch to Atom One Dark (after installing Material Theme UI, & restarting):

Open Preferences => Appearance & Behavior => Material Theme and change Selected Theme to Atom One Dark.

Copy ZiggyStardust.tmTheme to ~/Library/Application\ Support/Sublime\ Text\ 3/Packages/User

Copy or symlink Atom/ziggy-stardust-syntax:

$ ln -s Atom/ziggy-stardust-syntax ~/.atom/packages

Copy or symlink VisualStudioCode/ziggy-stardust:

$ ln -s VisualStudioCode/ziggy-stardust ~/.vscode/extensions

Instructions

Copy the file to ~/Library/Developer/Xcode/UserData/FontAndColorThemes/.