Cyberduck is a mature, multi-protocol file transfer client for macOS, Windows, and Linux (CLI). It supports over 30 storage protocols including S3, SFTP, FTP, WebDAV, Azure, Google Drive, Dropbox, Backblaze B2, and many more. The architecture is a Java core library with platform-specific UI bindings: Cocoa for macOS (via Rococoa/JNA), WinForms/WPF for Windows, and a command-line interface (duck). The core defines a clean set of feature interfaces (Read, Write, Find, Delete, etc.) that each protocol module implements, enabling a uniform file operation model. The system also integrates client-side encryption via Cryptomator vaults, which wrap protocol features transparently using decorator patterns. Key external dependencies include Apache HttpClient, JSch (SSH), and various cloud SDKs.
HydroShare is a Django-based web application for sharing, managing, and publishing hydrologic data and models. It provides a rich resource management system with support for various file types (NetCDF, GeoTIFF, timeseries, etc.), fine-grained access control (groups, communities, privileges), metadata extraction, and discovery via a Vue.js frontend. The system uses PostgreSQL, Redis, Celery, MinIO (S3-compatible storage), and MongoDB for indexing. It exposes REST APIs for programmatic access and includes background tasks for bag creation, metadata extraction, and DOI registration. While primarily an application, it incorporates data engineering patterns for scientific metadata handling and file type aggregation.