GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.

TestRail - TestRail provides comprehensive test case management for software testing. Organize your testing, boost productivity, get real-time insights, and track progress toward milestones. Integrates with leading issue tracking and test automation tools.

GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab

Micro Focus ALM - Learn how Micro Focus’ Application Lifecycle Management (ALM) software tools provide the agility, visibility, and collaboration solutions you need to optimize app development and testing, foster innovation, and improve the user experience.

BitBucket - Bitbucket is a free code hosting site for Mercurial and Git. Manage your development with a hosted wiki, issue tracker and source code.

Helix ALM - Helix ALM is the single, integrated application that lets you centralize and manage requirements, test cases, issues, and other development artifacts and their relationships.