The .ODT file extension refers to files of the type OpenDocument Text documents. These are the opensource word processing documents created typically by the Writer software.

The Odt documents are similar to word documents created by Microsoft word, they differ in the sense that it is open source and uses XML formatting for the file structure.These are widely supported by the modern operating systems and can be opened in a variety of open source word processing software. The file is designed with the OASIS openDocument XML specification.