About PIE Framework
Portable Interactions and Elements — an open-source framework for rendering and authoring interactive assessment items
PIE in brief
PIE renders assessment content in the browser: the question types, their authoring views, and the players that deliver them. You bring the backend: content storage, authentication, scoring service, reporting and infrastructure. Element controllers and the text-to-speech server packages can run on your servers.
Key differentiators
- Graphical authoring — Authoring views for 30 of the 31 element types; hosts pair them with a live delivery preview
- Framework-agnostic — Custom elements work with React, Vue, Angular, Svelte, or plain JavaScript
- Accessibility first — Elements are built for keyboard navigation, screen readers and high-contrast color schemes
- Production-ready — Powers some of the highest-volume assessment platforms in education
Standards alignment
- QTI interoperability — PIE-QTI provides QTI 2.2 and 3.0 item and assessment players (pre-1.0) alongside bidirectional transforms
- QTI-inspired architecture — Section and assessment models follow QTI 3.0's test parts, sections and item references
- WCAG 2.2 AA — Built to WCAG 2.2 AA. Automated axe checks cover every element and the item, section and assessment players, and their findings are being worked down; manual assistive-technology validation is in progress. Accessibility docs(opens in new tab)
- LTI compatible — PIE players run inside an LTI tool; the tool host handles the launch, Deep Linking and grade passback. LTI integration guide(opens in new tab)
Web standards
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. The item player loads elements as IIFE bundles, as ES modules, or preloaded by the host; loading strategies(opens in new tab) compares them.
Custom elements
Framework-agnostic HTML tags for every player and element
IIFE bundles
Pre-built element bundles from the PIE bundle host; the item player's default
ES modules
Static browser builds from a CDN, with shared dependencies through an import map
JSON
Item configuration, session state and API communication
npm
Package distribution and dependency management
The PIE ecosystem
PIE Elements
31 element types: 26 question types plus passages, video stimulus and three rubric elements. Each ships a delivery view and a controller; 30 add an authoring view and 12 a print view.
- Multiple choice, constructed response, math entry
- Drag-and-drop, graphing, hotspot
- Authoring views that emit every change for a live preview
- Partial credit scoring and feedback
PIE Players
Composable players that each host assembles into its own assessment experience
- Item player with three loading strategies
- Section players for page-level composition
- Print player for printable versions of items
- A reference assessment player that shows one assembly
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
- AfA PNP 3.0 accommodation model (as used by QTI 3.0)
PIE-QTI
Sibling project providing QTI players and bidirectional transforms with a version-agnostic architecture
- QTI 2.2 and 3.0 item and assessment players (pre-1.0)
- Auto-detection of the QTI version from the XML
- Plugin-based transform engine with a CLI (in development)
- 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
MIT licensed
PIE is MIT licensed (legacy pie-elements and pie-lib: ISC). Use, modify and distribute it 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