Pure reference catalog for picking a test automation framework - covers Playwright / Cypress / Selenium / WebdriverIO / Appium / Espresso / XCUITest / RestAssured / Karate / k6 / Locust with side-by-side tradeoffs on speed, cross-browser, mobile, parallelisation, language support, ecosystem maturity, CI integration; a decision tree for matching project NFRs to framework choice; and reference directory / fixture / CI layouts for the chosen stack. This is the **upstream selection step**: it decides which tool to adopt, not how to configure a tool already chosen, and not how to rebalance the unit / integration / E2E mix of an existing suite. Use when starting a new test-automation suite from scratch, before installing any tool.