This is a list (most likely incomplete) of extant classroom response systems, with comments on some of them.

On 2007-10-05, we updated all the links. We have NOT recently updated the list of systems represented here, or re-informed our opinions about them. If you know of any classroom response systems that belong on this list, or want to update us on the status of one listed here, we'd love to know. Thanks! -- ed

This list includes dedicated classroom response/communication systems, as well as presentation and distance learning systems that have question-posing, response-gathering functionality. If you know of a system we haven't listed here, please let us know and tell us where to find more information.

Opinions and notes about the various systems are our current impressions only. Many are based on only a shallow review of online literature, and may not do justice to the system. They are included here to help the reader (and ourselves) begin to categorize and make sense of the myriad options available.

Commercial

Calculator Clients (proprietary network)

Classtalk by Better Education (Discontinued)
The granddaddy of CCS... Ahead of its time with its rich feature set and pedagogic support, but plagued by a finicky proprietary network and fragile software. No longer in use at UMass.

TI-Navigator by Texas Instruments
A wired-plus-wireless network for connecting TI graphing calculators to a teacher's computer in order to distribute problem sets, share results, etc. Aimed primarily at the K-12 market. Not suitable for large university classes.

Proprietary, Dedicated Clients (mostly infrared-based)

PRS and PRS-RF by InterWrite (GTCO CalComp)
Infrared system using a proprietary remote control ("clicker"), supporting only multiple-choice answers with low/normal/high confidence level. They've just come out with a new RF-based system that looks pretty darn nice, and we've chosen it for our TLT project. Control software now runs on Mac as well as Windows. Used extensively at UMass.

CPS by eInstruction
Similar to PRS, though we found annoying shortcomings in the software (possibly resolved by the time you read this: the software is under active development).

H-ITT by Hyper-Interactive Teaching Technology
Supposedly an alternative to PRS with much less expensive "clickers"

ACTIVote by Promethean
Unknown.

Qwizdom by Quizdom, Inc.
Unknown.

Laptop/Tablet/Palmtop Clients (Ethernet/WiFi)

Discourse by ETS
Discontinued??

Silicon Chalk by Horizon Wimba
Unknown.

Pocket Classroom & LearnTrac by eLearning Dynamics
PDA-based CCS (Pocket Classroom is for iPaq-type devices, LearnTrac is for PalmOS devices) with relatively simple polling, statistical reporting, and messaging capabilities. (Discontinued??)

SmartTRAX by LearnStar
Unknown.

Virtual Rooms by Hewlett-Packard
Unknown.

DyKnow
Essentially a shared-whiteboard system, sending contents of an instructor's electronic whiteboard (or tablet PC) to students and allowing students' drawings to be returned to the instructor or shared with the class. Claims some support for multiple-choice questions with answer reporting to the instructor, as well as assignment-submission and grading. MS Windows only.

Cell Phone Clients (SMS + Web)

Poll Everywhere
Students use their own cell phones to send SMS text messages with their question responses, and the instructor uses a web site to see results. Priced for access to the web site/service, according to the maximum number of students to be permitted in a class.

Noncommercial/Home-Grown

Numina by the University of North Carolina at Wilmington
Unknown.

Classroom Presenter by the University of Washington
Primarily presentation software (PowerPoint on steroids) taking advantage of the tablet PC's inking abilities. Has added some support for sending questions to a class and gathering answers, by means of multiple-choice questions that are "inked" to indicate an answer, and gathered back to the instructor. Not a full-featured CCS in the classic sense.

Beyond Question by Erskine College
Unknown.

ActiveClass by University of California at San Diego
Subsumed into the ActiveCampus project? Discontinued??

Sledgehammer by Purdue
PDA-based CCS: discontinued? Vaporware??