EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT Auto-trol Technology Corporation, a Colorado corporation, has the following subsidiaries, incorporated in the jurisdictions noted and doing business under the names indicated: SUBSIDIARY JURISDICTION OF INCORPORATION ---------- ----------------------------- Auto-trol International Corporation Colorado Centra 2000, Inc. Colorado Auto-trol Technology (Canada) Ltd. Alberta Auto-trol Advertising, Inc. Colorado Auto-trol Technology GmbH Germany Centra Technology Ltd. United Kingdom