ICTAC is an International Colloquium on Theoretical Aspects of Computing founded by the International Institute for Software Technology of the United Nations University (UNU-IIST).

The aim of the colloquium is to bring together practitioners and researchers from academia, industry and government to present research results, and exchange experience, ideas, and solutions for their problems in theoretical aspects of computing. We believe that this will help developing countries to strengthen their research, teaching and development in computer science and engineering, improve the links between developing countries and developed countries, and establish collaboration in research and education.

The first ICTAC (ICTAC 2004) was held in Guiyang, China and its proceedings were published as "ICTAC 2004: Theoretical Aspects of Computing", LNCS 3407. The second ICTAC (ICTAC 2005) was held in Hanoi, Vietnam and its proceedings were published as "ICTAC 2005: Theoretical Aspects of Computing", LNCS 3722.

ICTAC 2006 is organized by the International Institute for Software Technology of the United Nations University, the University of Tunis El Manar, the Ecole Nationale d'Ingénieurs de Tunis, the University of York and the CNAM Paris.