There are several programming languages used for machine learning, including:

Python: Python is one of the most popular languages for machine learning. It has a vast number of libraries and frameworks, such as TensorFlow, Keras, and Scikit-Learn, which make it easy to build machine learning models.

R: R is another popular language for machine learning. It has a vast number of libraries, such as ggplot2 and caret, which make it easy to visualize data and build machine learning models.

Java: Java is a versatile language that is used for building large-scale machine learning applications. It has several popular machine learning libraries, such as Weka and Deeplearning4j.

C++: C++ is a fast and efficient language that is commonly used for machine learning libraries and frameworks, such as TensorFlow and OpenCV.

Julia: Julia is a relatively new language that is gaining popularity in the machine learning community due to its speed and ease of use.

In summary, Python and R are the most commonly used languages for machine learning, followed by Java, C++, and Julia.