ROOT is an object-oriented program and library developed by CERN. It was originally designed for particle physics data analysis and contains several features specific to this field, but it is also used in other applications such as astronomy and data mining.

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. However, roots can also be aerial or aerating (growing up above the ground or especially above water). Furthermore, a stem normally occurring below ground is not exceptional either (see rhizome). Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plant's body. However, important internal structural differences between stems and roots exist.

root is the name of a database record of the root zone in the Domain Name System of the Internet that was occasionally used as a diagnostic marker. Its presence demonstrated the root zone was not truncated upon loading by a root nameserver.

The Filesystem Hierarchy Standard (FHS) defines the directory structure and directory contents in Unix and Unix-like operating systems. It is maintained by the Linux Foundation. The latest version is 3.0, released on 3 June 2015. Currently it is only used by Linux distributions.

Root! (stylised ROOT!) was an Australian rock group from Melbourne formed in 2004. Their music combines alt-country, blues and indie rock with elements of spoken word, satire, social commentary and post-modernism. They have gained attention through a band member being a former member of Melbourne band TISM.