CodeStream is a tool that helps remote developers collaborate and communicate more effectively by integrating with popular IDEs. It allows users to have ongoing conversations about code blocks through "Codemarks," which can be comments, issues, permalinks, or bookmarks, providing flexibility and insight into the codebase. Additionally, CodeStream enables easy sharing of Codemarks on Slack and Microsoft Teams, quick identification of who last worked on a code block, real-time code reviews with full source tree context, integration with existing tools and workflows, instrumentation of code for production error debugging, live-debugging of production environments from the code editor, and more. With its free and open-source nature, CodeStream aims to improve software development workflows and productivity.