Opening and saving files: GS-Calc and ODF files

GS-Calc can optionally use both its private binary file format and the ODF format as its native format.

GS-Calc (*.gsc)

Typically GS-Calc *.gsc files should be several times smaller than the corresponding ODF files. Thanks to various special compression techniques for certain files that difference can even reach several hundreds times or more. Similarly loading/saving times are much faster when this file format is used.
GS-Calc files are plain zip files that contains several zip streams including the workbook data, used images, the list of files (along with optional encryption information), the current file version number, the minimal GS-Calc version required to open it and the thumbnail image. The thumbnail path is: Thumbnail/thumbnails.png.
If the file is encrypted, both the workbook data and all used images are encrypted.
The *.gsc format is a private binary format and it's not supported by other applications.

To associate the *.gsc file type with GS-Calc in Windows, you must register that file type in the Windows registry database. To do this, run GS-Calc as an administrator (e.g. right-click GS-Calc shortcut/icon and on the context menu choose "Run as administrator") and use the Settings > Register GS-Calc *.gsc File Type command.
Similarly, if you no longer need that registration, you can use the Settings > Unregister GS-Calc *.gsc File Type command to remove all registry entries added earlier.

Open Document Format (*.ods)

Saved files conform to the ODF 1.2 specification. This is a standard file format used by several notable applications. There are several GS-Calc-specific features that depends on preserving some element naming (which otherwise are not required to be preserved when a given file is re-edited by other applications). Those features include:

GS-Calc enables you to specifies which formula notation should be used when saving newly created *.ods files.
You can choose one of the following formula "namespaces":
Excel 2010/2013 ("msxol:"),
OpenFormula ("of:"),
Google Docs ("oooc:").
When editing existing *.ods files GS-Calc will preserve their current formula notation. To change it you can use the Save As command.
Choosing the right formula namespace might be important as, for example, opening an "OpenFormula" file in Excel might result in removing the formulas and replacing them with their current values.
This options can be specified either during the setup or later via the Setting > Options dialog.

Related Topics

Excel (*.xlsx, *.xml, *.xls) files
GS-Base (*.gsb) files
PDF files
Text files (*.csv, *.txt, *.tab ...)
Text *.zip archives
dBase/Clipper/FoxPro files
MySQL (*.sql) files
SQlite (*.db) files