
Description: Charcoal is a minimalist drawing software focused on digital sketching and concept art creation. It offers an intuitive interface for fast drawing, uses graphics tablet stylus pressure for natural drawing strokes, and has useful tools for basic operations like layers, shapes and colors.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Interference is an open-source alternative to Figma for interface design, prototyping, and collaboration. It provides vector design tools and adaptive layout grids to design responsive web and mobile apps.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API