TORONTO, November 23, 2004

New Senior Officer and Director Appointed by ACD/Labs

Advanced Chemistry Development, Inc., (ACD/Labs) announces the appointment of Dr. Antony Williams, former Vice President of Scientific Development and Marketing, to the position of VP and Chief Science Officer. Antony has been responsible for leading both business and product development at ACD/Labs for over 8 years and specifically developing the ChemAnalytics platform. In his new role, Dr. Williams will further expand on the impact of ACD/Labs at the desktop of every chemist. This will be enabled by the delivery of both desktop and enterprise solutions which deliver ACD/Labs core strengths through innovative new platforms.

Coinciding with this announcement is the appointment of Dr. Mark Bayliss, former Product Manager for Mass Spectrometry, to the position of Director of Analytical Informatics. This new role will provide a unified direction to the entire ACD/SpecManager team to ensure the continued development of the ChemAnalytics platform as an integrated way to integrate structure, expert level data processing, databasing, reporting, and information dissemination across all scientific disciplines. In parallel, this role further enables the development of the company's vision towards providing complete solutions at the chemist's desktop and the Enterprise level by way of an integrated suite of tools meeting the needs of scientific organizations worldwide.

Dr. Williams states, "I am privileged to work in an environment of innovation and scientific strength at ACD/Labs. This company's commitment to deliver visionary software to scientists has driven ACD/Labs to be one of the premier scientific software developers in the marketplace today. I look forward to leading the ACD/Labs team forward to execute further on the vision of enabling collaborative science across an organization."

Dr. Bayliss adds, "For 10 years ACD/Labs has continually expected and empowered its employees to develop industry leading scientific software that delivers high value, expert level science and productivity to our customers. Our software solutions are driven by an amazing group of individuals from Technical Support, Marketing, Product Management, and our Development Team, all of whom are experts in their own fields. I look forward to enabling the Product Management and Development Teams to continue to drive the expansion and integration of our ChemAnalytics platforms with our Enterprise solutions based on our customer needs."