
Description: The W3C Markup Validation Service is a free tool that checks HTML and XHTML documents for conformance to W3C standards. It can help identify potential issues in web pages and ensure they use valid markup.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Scrutiny is an open-source alternative to Photoshop focused on non-destructive editing and photo retouching. It has layers, masks, filters and tools for image manipulation.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API