Which of the following is not a Web browser?

A web browser is a software application used to access and view websites on the Internet. Popular examples include Google Chrome, Mozilla Firefox, Microsoft Edge, Safari, and the legacy Internet Explorer.

MapReduce, on the other hand, is completely unrelated to web browsing. It is a core software framework and programming model originally developed by Google. It is used for processing and generating massive datasets with a parallel, distributed algorithm on a cluster. It forms a fundamental part of big data ecosystems like Apache Hadoop.