
Description: MuPDF is a free, open source PDF viewer and toolkit. It is lightweight, fast, and cross-platform, supporting Windows, macOS, Linux, Android, and iOS. MuPDF allows you to view PDFs quickly and smoothly while using minimal system resources.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: STDU Viewer is a free portable software used to open and view various file types like PDFs, images, Microsoft Office documents, emails, archives, EPUB books and more. It supports viewing over 20 file formats and includes features like tabbed browsing, thumbnail previews, bookmarks and annotations.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API