Definition(en): Vim SWAP file is a temporary file created by the open source Vim text editor, when editing a file. The file's name typically begins with ".", and ends with ".swp". The file is normally deleted when editing is complete, but may be left behind in the event of a crash or other abnormal termination. Its main purpose is to periodically record unsaved changes made to the file. It also serves as a lock file. The file format is undocumented, and not necessarily portable. Vim is free and open-source, screen-based text editor program for Unix, released to the public in 1991. Vim was designed for use both from a command-line interface and as a standalone application in a graphical user interface.