curl/curl

curl is a command-line tool and library for transferring data with URL syntax, supporting a wide range of protocols including HTTP, HTTPS, FTP, SFTP, SMTP, and WebSocket.

The tool solves the problem of reliably transferring data across networks by providing a unified interface that works with multiple protocols through URL syntax. Rather than requiring different tools for different protocols, curl abstracts the protocol layer so users can work with a consistent command-line interface. libcurl, the underlying library, handles the actual protocol implementation and can be embedded in other software to add data transfer capabilities.

Developers should choose curl if they need a lightweight, widely-compatible solution for data transfer in scripts, applications, or command-line workflows. It suits projects ranging from simple HTTP requests to complex multi-protocol scenarios. The tool is particularly valuable in environments where a single dependency can handle numerous transfer protocols, reducing the need to maintain separate libraries for FTP, SMTP, SFTP, and other services. Commercial support is available for organizations requiring dedicated assistance.

The project maintains active engagement across multiple communication channels including mailing lists, GitHub issues, pull requests, and discussions. Security vulnerabilities are handled through a private disclosure process rather than public reporting. The project acknowledges contributions through a dedicated THANKS document and accepts financial backing through both individual backers and sponsors.