Skip to content


Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


Join the chat at Join the chat at

A brand new client side Web UI framework for Haskell that explores an entirely new paradigm. It does not follow FRP (think Reflex or Reactive Banana), or Elm architecture, but aims to combine the best parts of both.


Work in progress tutorials are published in the Concur Documentation site


It has three backends -

  1. React based, called concur-react. You can use the Concur-React Quickstart Template to quickly get started.

    An example of using Native React Widgets is here - Drag Drop Sortable List Widget (React) - Demo - Demonstrates Concur binding to React-Sortable-Tree.

  2. Virtual-Dom based, called concur-vdom. (Bitrotten). You can use the Concur-Vdom Quickstart Template to quickly get started.

  3. Replica (i.e. remote virtual-dom) based, called concur-replica. Created and maintained by pkamenarsky. Head to its project page for more information.


Access some performance benchmarks here -

Ports to other languages

Concur's model translates well to other platforms.

  1. Concur for Purescript - An official port to Purescript which is well maintained.
  2. Concur for Javascript - An official but experimental port to Javascript.
  3. Concur for Python - An unofficial and experimental port to Python. Uses ImgUI for graphics. Created and Maintained by potocpav.


  1. Click Counting Example - Demo - Count total number of clicks on the page, with a button that increments the click count by 10, and also autoincrement clicks every second.
  2. TodoMVC Example - Demo - The canonical TodoMVC example, with views modeled after the one in Elm.
  3. Mario Example - Demo - Port of the Mario example from Elm.
  4. High/Low Game (Virtual-dom) - Demo - An extremely simple number guessing game in 15 lines of code.
  5. High/Low Game (React) - Demo - The same HiLo game, using the React backend.
  6. Kirby Super Star Ultra Splits Timer GUI Challange - Demo - Concur implementation of the KSSU Splits Timer GUI Challenge. Shows a moderately complex UI that's not a todolist!
  7. Menu Widget (React) - Demo - Builds a generic menu widget in 10 lines of code.
  8. Drag Drop Sortable List Widget (React) - Demo - Demonstrates Concur binding to React-Sortable-Tree. A good example of reusing existing React components in Concur.
  9. Your first 8 Concur Pipes Widgets (React) - Demo - Your first 8 Concur Pipe programs! Inspired from the mighty Fudgets' -