Closes the project and all open tabs. If one or two files are modified, then for each modified file, you will be asked whether to save the file to disk before closing. If three or more files are modified, then the common save dialog appears, where you can choose with a checkbox for each modified file whether to save it or not. The checked files will be saved when you click OK in this dialog. If you click Cancel in this dialog, the files will stay open.
Always available.