Dia follows the saving model common to most desktop applications: you must explicitly save any canvases that you wish to retain for future use. To save a file, choose File Save from the Main Popup Menu. The result is a standard save dialog. Your canvas is saved in Dia XML format. No file extension is automatically added, so it is a good idea to explicitly add '.dia' to the name you enter. To load a canvas from a file previously saved by Dia or created by another application, select File Open... from the Main Menu Bar. The result is an open dialog; select the file you want and choose Open. The open dialog is standard apart from the popup menu labeled Determine file type. Choose the format of the file to open (Dia XML or Drawing Interchange) if Dia does not correctly determine the file format unassisted. An alternate file-loading method is to start Dia from the command line with the name of the file to open given as an argument. A few words on file types are in order. You should be aware that not all format of files can be re-loaded into Dia after saving and that most supported file formats lose information to some degree. The only format guaranteed to be lossless is Dia XML. Happily, you are unlikely to accidentally save in a lossy format because File Save always produces a file in Dia XML format. Files in Dia XML format are automatically compressed using gzip to save disk space. This is almost necessary since, without compression, even simple diagrams are very large because they store much redundant information. Because Dia XML files are already compressed, you should not try to compress them manually—it will not help. Dia supports exporting to many other types of file, such as: Computer Graphics Metafile HPGL EPS PNG SVG TeX WPG Dia cannot load files in these formats. These formats are useful for diagrams that you need to use in another application or to distribute to users of another operating system that Dia does not support. To create a file in one of these formats, select File Open... from the Main Popup Menu. Choose a name and the desired format in the resulting dialog, which works like a save dialog. An appropriate file extension is automatically added.