About PIE Framework
Portable Interactions and Elements — a modern, open-source frontend framework for rendering interactive assessment items
What is PIE?
PIE is an open-source frontend framework for rendering interactive assessment items. Unlike commercial platforms that bundle frontend, backend, and hosting into a single service, PIE focuses exclusively on what appears in the browser: the question types, authoring interfaces, and delivery players. You bring your own backend — your content management system, your item bank, your assessment administration platform, your authentication system, your scoring engine, your infrastructure.
Key Differentiators
- • WYSIWYG Authoring — Graphical authoring interfaces with live previewing built right in
- • Framework-Agnostic — Web Components work with React, Vue, Angular, Svelte, or vanilla JS
- • Accessibility First — Every element includes keyboard navigation, screen reader support, ARIA labels, and high-contrast compatibility
- • Production-Ready — Powers some of the highest-volume assessment platforms in education
Standards Alignment
- • QTI Interoperability — PIE-QTI provides production-ready QTI 2.x and 3.0 players alongside bidirectional transforms
- • QTI-Inspired Architecture — Section and assessment models map naturally to QTI 3.0 structures
- • WCAG 2.2 Level AA — Comprehensive accessibility throughout elements, players, and toolkit
- • LTI Compatible — Players can be embedded in LTI tools for LMS integration
How Does it Work?
PIE adopts web standards wherever possible. All players and elements are distributed as HTML5 custom elements, integrating into any web page as standard HTML tags.
Custom Elements
W3C Web Components standard for framework-agnostic UI
ES Modules
Native browser imports with tree-shaking and caching
JSON
Item configuration, session state, and API communication
NPM
Package distribution and dependency management
The PIE Ecosystem
PIE Elements
20+ production-ready question types with delivery, authoring, and controller interfaces
- Multiple choice, text entry, math expressions
- Drag-and-drop, graphing, hotspot
- WYSIWYG authoring with live preview
- Partial credit scoring and feedback
PIE Players
A layered player hierarchy from individual questions to full assessment delivery
- Item player with multiple loading strategies
- Section player for page-level composition
- Assessment player for multi-section orchestration
- All delivered as Web Components
Assessment Toolkit
Composable services for tools, accommodations, and accessibility coordinated through ToolkitCoordinator
- Calculator, ruler, protractor, graph tools
- Text-to-speech with word-level highlighting
- Annotation toolbar and answer eliminator
- QTI 3.0-inspired PNP accommodation model
PIE-QTI
Sibling project providing QTI players and bidirectional transforms with version-agnostic architecture
- QTI 2.x and 3.0 item and assessment players
- Auto-detection of QTI version from XML
- Plugin-based transform engine with CLI
- IMS Content Package support
Development History
The PIE Framework originated from work by CoreSpring.org in building authoring and rendering tools for assessment interactions. It was created as an open source project to help educators have better access to high-quality and more interactive assessment interactions, designed to be compatible with the approach suggested by Smarter Balanced in their ARI (Accessible Rendering and Interoperability) proposal.
Since those early days, PIE has been consistently sponsored and developed by a sizable team of full-time developers, with Renaissance (previously Illuminate Education) as the project's primary sponsor. The framework continues to evolve with modern web standards and educational needs.
Today, PIE powers assessment delivery at enterprise scale, serving approximately 40% of U.S. schools and processing hundreds of millions of student interactions annually. The framework's eight-year development history reflects continuous refinement based on production feedback — features like the section player composition model, the ToolkitCoordinator, the multi-strategy item player architecture, and QTI-inspired accommodation resolution all emerged from real operational requirements.
Open Source
ISC & MIT Licensed
PIE is licensed with permissive open source software licensing — ISC and MIT. Use, modify, and distribute freely for any purpose, including commercial use, without fees or royalties.
PIE's primary sponsor, Renaissance, aims to accelerate learning for all children and adults of all ability levels and ethnic and social backgrounds, worldwide. Contributing PIE as open source supports that mission, and we welcome the community to help make the framework even better.
- Use commercially without restriction
- Modify and customize freely
- No royalties or fees ever
- Active development by full-time team