SFCC Studio has features such as script debugging, code synchronization, syntax highlighting, auto complete and more...
Using IDE built-in plugin system:
Preferences > Plugins > Marketplace > Search for "sfcc-studio-template" > Install Plugin
Manually:
Download the latest release and install it manually using Preferences > Plugins > ⚙️ > Install plugin from disk...
File > Settings > Tools > Commerce Cloud Cartridges
File > Settings > Tools > Commerce Cloud Server
This project is now Gradle based and is much easier to get the development environment setup to work on the plugin. You should only need to import the project in either Intellij Community or Intellij Ultimate and execute the runIde Gradle task. For more information please see the official Jetbrains plugin development documentation.
http://www.jetbrains.org/intellij/sdk/docs/tutorials/build_system.html
https://plugins.jetbrains.com/plugin/11590-salesforce-commerce-cloud-studio