Developer tools that support multiple languages generally have very limited regex-based code-analysis capabilities. Tree-sitter is a new parsing system that aims to change this paradigm. We're in the process of integrating Tree-sitter into both GitHub.com and Atom, which will allow us to analyze code accurately and in real-time, paving the way for better syntax highlighting, code navigation, and refactoring support. We'll demo some new features that Tree-sitter has enabled in GitHub.com and Atom, discuss its implementation, and share thoughts on ways it could be used in the future.