
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: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: MJ PDF Reader is a free, lightweight PDF viewer for Windows. It allows you to view, print, and annotate PDF documents. Key features include tabbed browsing, search, bookmarks, and basic annotation tools.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API