A file extension is an addition to a computer file name. It is appended to the file base name following a dot "." and is mandatory on Windows systems. The SDR file extension illustrates a shortfall in the administration of file extensions. There is no international body ensuring the uniqueness of file extension as there is for Web and Internet addresses. Consequently, different file types may use the same file extension. As of March 2011, there are five different applications using the SDR file extension.
Dell computers shipped with Windows Server 2003 already installed have a dell.SDR file in the C:\ root directory. This file is a marker indicating the Windows Server 2003 software was factory-installed. It is not an important file and can be deleted or renamed.
SmartDraw is a graphics package. The program is produced by a company of the same name. It enables users to produce a wide variety of drawings, including charts and floor plans. The company stresses the program's features for creating presentations, guided by templates and wizards. They describe SmartDraw as a visual processor, offering the graphics equivalent of a word processor. The default file extension for a drawing created in and saved by SmartDraw is SDR.
Sounder is a Windows-based music creation program. The program creates ambient music based on the movement of shapes represented as animation in the user interface. A Sounder-saved music file has the SDR file extension.
Sound card drivers for QuickView Pro use the SDR file extension. QuickView Pro was created by Multimediaware. It is a DOS-based multimedia viewer for playing video or music files. The viewer can process files formatted as DivX, AVI, MPEG, MOV or MP3.
Smart Diary Suite
Programming Sunrise produces a diary program called Smart Diary Suite. It is a system to note down appointments and anniversaries. Smart Diary Suite also has a writing section where users can record their thoughts or events of the day. Another section allows those notes to be recorded and stored as sound files. In Smart Diary Suite, reminders are saved in files with the SDR file extension.