jtree

A toolbox for running economics experiments. Download the archive for your computer, unpack it, and run the launcher in the unpacked folder. Node.js is included; nothing needs installing.

Download	Then run
Windows	`start.cmd`
macOS, Apple Silicon (M1 and later)	`start.command`
macOS, Intel	`start.command`
Linux, x86-64	`start.sh`
Linux, ARM64	`start.sh`
Any system with Node.js 22+	`start.sh` or `start.cmd`

The admin page opens in your browser, at http://localhost:3000/admin/. On macOS, the first time, right-click start.command, choose Open, and confirm. Older versions (0.8.7 and before) are on the releases page.

Features

participants only need a browser; the server runs on Windows, macOS and Linux.
apps in Javascript, with an app editor in the admin: an app as a tree of its stages, their screens and the elements on them, as z-Tree and oTree Studio show theirs, or as forms, or as source.
runs z-Tree treatments and oTree apps as they are, edits them as z-Tree and oTree Studio do, and converts them to jtree apps.
three admin interfaces: jtree’s own, one laid out after z-Tree, and one after oTree’s.
a samples library: 23 economics experiments (public goods, trust, auctions, markets, …), each written for jtree, oTree and z-Tree alike.
GIMS asset markets: the Graz-Innsbruck Market System’s generic asset market, with presets for 81 published designs (Smith, Suchanek and Williams 1988 and the studies after it).
autoplay and bots for testing.
rooms: permanent links for participants.
queues: sequences of apps, with their options, for re-use.