SurveyJS Form Library is a production-grade, multi-framework JavaScript library for creating, rendering, and managing dynamic forms and surveys entirely in the browser. The core package (`survey-core`) provides a comprehensive model layer including serialization via decorators (`Serializer`), a custom expression engine for conditional logic and validation, a static analysis linter for survey JSON definitions, input masking, drag-and-drop, theming (CSS variables with adapters for Bootstrap/MUI/shadcn), and even a real-time collaboration plugin with presence and value sync. UI packages deliver identical rendering across React, Angular, Vue 3, and vanilla JS (Knockout/jQuery). The architecture is a monorepo: the core is framework-agnostic, while UI packages bind to their respective component models. Data flows from JSON definition → deserialization into model → user interaction → validation → result output (also JSON). The test suite is extensive (unit, E2E, accessibility, visual regression) and the library is actively maintained with weekly releases.