JaCoCo (Java Code Coverage) is an open-source tool used for measuring and reporting code coverage in Java applications. Developed by the Eclipse Foundation, it integrates seamlessly with popular build tools like Maven and Gradle, as well as continuous integration (CI) pipelines. JaCoCo is invaluable for assessing the effectiveness of automated tests and ensuring robust code quality.

Core Features
1. Code Coverage Metrics: Measures line, branch, and instruction coverage to highlight untested parts of code.
2. Integration: Works with IDEs, CI/CD pipelines, and build systems to automate coverage analysis.
3. Customizable Reports: Generates detailed reports in HTML, XML, and CSV formats for analysis and auditing.
4. Runtime Instrumentation: Uses runtime bytecode instrumentation to collect coverage data without modifying source code.

Use Cases
- Test Quality Assurance: Helps developers identify gaps in test cases and improve overall test coverage.
- CI/CD Pipelines: Automates coverage checks during builds to maintain high code quality standards.
- Compliance and Auditing: Provides coverage reports required for software certifications and audits.

Advantages
- Lightweight and easy to integrate into existing workflows.
- Compatible with tools like SonarQube for advanced code analysis.
- Provides actionable insights into test coverage and code maintainability.

By incorporating JaCoCo, development teams can enhance their testing strategies and ensure their applications are thoroughly validated before deployment.