Surge

Surge is a Mac network toolbox. Its official website describes it as an advanced web debugging proxy for Mac and iOS.

The supplied Homebrew package is the surge@4 cask, which installs Surge.app in /Applications. It is a specific Surge 4 package, distinct from the unversioned surge cask; the two casks are listed as conflicting.

• The official product description identifies web debugging proxy functionality for Mac and iOS.
• The package is provided as a macOS application bundle.
• Homebrew's cask declares a macOS dependency and includes uninstall handling for a Surge helper tool.

To install this specific cask, run brew install --cask surge@4. Open Surge.app from Applications to get started. The official site provides no further product details in the supplied source material.

Sources: Official Surge website · Homebrew cask for surge@4