TurtleResponder & TurtleMessenger: a classroom response system


Downloads (version 2016-01-18):

TurtleResponder binary
(Software for students)

Unix(jar file)
Android(apk file)

TurtleMessenger binary
(Software for teachers)

Unix(jar file)

source file


This page is to introduce a simple open-source software tool to collect responses from students in computer laboratories like a "clicker."


This tool consists of a couple of application software; one is TurtleMessenger for instructors*, and the other, TurtleResponder, for students. The both software require Java 6 JRE, or higher, to execute.

*Instructors should be aware that students do not install TurtleMessenger intentionally or unintentionally on their computers.

All the computers or devices in a class room need to be connected to the same IP subnet. Communication using TCP/UDP port 3100 and TCP port 3080 has to be allowed.

Usage of this tool is fool proof. Take a look at the following documents for details.



Java 6 (JRE), or later (download JRE)

To recompile source code, NetBeans(7.3 or later) is required.

If you get some warming message from firewall or malware detection utility, please allow this software to use TCP/UDP port 3100.

How to run it

Just double-click the application program for Mac/Windows versions.

In a Linux machine, execute the following command in terminal emulator

java -jar TurtleResponder.jar

Instructors use the following command

java -jar TurtleMessenger.jar


Android version:

What's new

An experimental version of TurtleResponder for Android is out (left fig.) Download its apk data and open it to install. Make sure that "Unknown sources" is checked in Settings > Applications. This software will send the email address stored in the Android tablet/phone to TurtleMessenger as a unique ID of students (2016-01-18).

When "Enable Web access" is checked on TurtleMessenger, students can read results of feedback in their web browser just by clicking globe icon on the window of TurtleResponder. TurtleMessenger uses TCP 3080 port for this purpose (2014-07-19).

Why I wrote this

This software is aimed to collect responses from students in computer labs without additional costs nor preparation beforehand. Although similar (or much better) software might be available in public domain, there seem to be few open source codes for such purpose. It is my great pleasure if you could utilize this tool to make your class more active.

TurtleResponder sends some private information including user account and hostname of user's PC to the local network. It is NOT recommended to use this software in public networks, even though that information is encrypted in the packets.

Yoshinori Hayakawa (CITE, Tohoku University)

TurtleMessenger, TurtleResponder are distributed under GPL3.0.

TurtleResponder and TurtleMessenger

Copyright (C) 2013-2016 Yoshinori Hayakawa <hayakawa@cite.tohoku.ac.jp>

These programs are free software: you can redistribute them and/or modify
them under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

These programs are distributed in the hope that they will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see http://www.gnu.org/licenses/.