Gensym's G2 Honored with Control Engineering Editors' Choice Award; Next-generation G2 software chosen as one of the top 40 new products of 2004.

BURLINGTON, Mass. -- Gensym Corporation (OTC Bulletin Board: GNSM), a leading provider of rule engine software for mission-critical solutions, today announced that the next generation of its G2 real-time rule engine, Version 8, has been selected by Control Engineering magazine as a 2004 Editors' Choice Award winner. Gensym's G2 software applies rule and other reasoning technologies to automate decisions in the most demanding real-time applications ranging from monitoring NASA's spacecraft operations to detecting and solving problems in El Paso Energy's 16,000 mile gas pipeline network to coordinating Toyota's automobile production in its worldwide facilities.

Control Engineering selected G2 as one of 40 award winners from the thousands of new products reviewed and featured by the magazine during 2004 in print, online, and in e-mail newsletters. Criteria used to select the winners includes: service to the industry, technological advancement, and market impact.

"These awards honor the most significant innovations featured in Control Engineering during the past year," said Mark Hoske, Control Engineering editor-in-chief. "Gensym's G2 clearly meets this criteria - the software advances the state-of-the-art for reasoning-driven applications that work in real time, including those that predict, diagnose, and respond to operational problems or that optimize the performance of complex operations."

"This award, which is ranked among the top in the automation industry, validates our strategy to provide the leading platform for mission-critical, real-time rule engine solutions," said Kim Mayyasi, president and CEO of Gensym. "A key aspect of our strategy is working closely with partners that combine their industry expertise with G2 to rapidly build and deliver a wide variety of mission-critical solutions."

About Gensym Corporation

Gensym Corporation (www.gensym.com) is a leading provider of rule-engine software and services for mission-critical solutions that automate decisions in real time. Gensym's flagship G2 software applies real-time rule technology for decisions that optimize operations and that detect, diagnose, and resolve costly problems. With G2, the world's largest organizations in manufacturing, utilities, communications, transportation, aerospace, finance, and government maximize the agility of their business and achieve greater levels of performance. Major users include ABB, Alcan, BP, Dow Chemical, DuPont, Ericsson, ExxonMobil, El Paso, Eli Lilly, Fidelity Investments, Ford, Hitachi, HP, JEA, Lafarge, Motorola, Nokia, Panama Canal, Tokyo Electric and Power, Toyota, the U.S. government, and many others. Gensym and its numerous partners deliver a range of services throughout the world, including training, software support, application consulting, and complete solutions.

Gensym and G2 are registered trademarks of Gensym Corporation. All other trademarks are property of their respective owners.

This news release contains forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are subject to risks and uncertainties, which could cause actual results to differ materially from those anticipated. Such risks and uncertainties include those detailed in Gensym's periodic reports and registration statements filed with the Securities and Exchange Commission. Although Gensym believes the expectations reflected in the forward-looking statements are based on reasonable assumptions, it can give no assurance that its expectations will be attained. Gensym Corporation disclaims any intent or obligation to update any forward- looking statement.