To view your installed packages or themes, open settings with Ctrl+, and select either the "Packages" or "Themes" tab in the left-hand navigation bar. Note, the packages or themes you installed from other publishers will show up under the "Community Themes" section and themes pre-installed with Atom will show up under the "Core Themes" section.
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)To view information on packages and their settings, click the package name.
Browse Atom packages online here.
Downloading and installing themes follows a similar process to that of packages.
atom-sublime-monokai-syntax
)To view information on themes and their settings, click the theme name.
Browse Atom themes online here.