Subsidiaries of the Registrant as of December 31, 2023

Jurisdiction of Organization

Altair Engineering, Inc.

United States

Datawatch Corporation

United States

Altair Product Design, Inc.

United States

Ilumisys Inc.

United States

Altair Bellingham LLC

United States

Altair Bellingham II, LLC

United States

Altair Bellingham III, LLC

United States

RapidMiner, Inc.

United States

Vanderplaats Research & Development, Inc.

United States

Altair Engineering Canada, Ltd.

Canada

Altair Engineering (Pty) Ltd.

South Africa

Informatica Altair Mexico S de RL de CV

Mexico

Altair Engneering do Brazil Sistemas e Servicos Ltda

Brazil

Altair Engineering AB

Sweden

Altair Software and Services S.L.

Spain

Altair Engineering GmbH

Germany

RapidMiner GmbH

Germany

Altair Engineering France SAS

France

RapidMiner Kft.

Hungary

Altair Engineering Srl

Italy

AD Solutions Srl

Italy

Altair Engineering Single Shareholder Ltd.

Greece

Altair Engineering Israel Ltd.

Israel

Altair Engineering Software Pty Ltd.

Australia

Altair Engineering Software (Shanghai) Co. Ltd.

China

Altair Engineering India Pvt. Ltd.

India

Altair Engineering Co. Ltd.

Korea

Altair Engineering Sdn. Bhd.

Malaysia

Altair Engineering Co., Ltd.

Taiwan

Altair Engineering Ltd.

Japan

Altair Engineering (Singapore) Ptd Ltd.

Singapore

Altair Technologies Philippines Inc.

Philippines

Gen3D Limited

United Kingdom

Altair Engineering Ltd.

United Kingdom

World Programming Limited

United Kingdom

December 2015 Software Limited

United Kingdom

RapidMiner Limited

United Kingdom