The irace package is a software tool designed for automatic algorithm configuration, particularly for optimizing the performance of modern optimization algorithms. The package implements iterated racing procedures, which have been successfully used to configure various state-of-the-art algorithms. The iterated racing procedures include the iterated F-race algorithm and several extensions, such as a restart mechanism to avoid premature convergence, the use of truncated sampling distributions to handle parameter bounds, and an elitist racing procedure to ensure that the best configurations are evaluated on the highest number of training instances. The paper provides a detailed description of the iterated racing procedure and its extensions, and evaluates the performance of the irace package through experimental studies. The results demonstrate the effectiveness of the irace package in automatic algorithm configuration, highlighting its potential for improving the design and performance of optimization algorithms.The irace package is a software tool designed for automatic algorithm configuration, particularly for optimizing the performance of modern optimization algorithms. The package implements iterated racing procedures, which have been successfully used to configure various state-of-the-art algorithms. The iterated racing procedures include the iterated F-race algorithm and several extensions, such as a restart mechanism to avoid premature convergence, the use of truncated sampling distributions to handle parameter bounds, and an elitist racing procedure to ensure that the best configurations are evaluated on the highest number of training instances. The paper provides a detailed description of the iterated racing procedure and its extensions, and evaluates the performance of the irace package through experimental studies. The results demonstrate the effectiveness of the irace package in automatic algorithm configuration, highlighting its potential for improving the design and performance of optimization algorithms.