Mathematica provides a uniquely powerful interactive environment for building up arbitrarily complex computations, under convenient interactive or programmatic control.

Building large software systems in Mathematica should follow the general principles that apply to building any large software system. The details may be unique to Mathematica ...

There will probably be times when you want to stop Mathematica in the middle of a calculation. Perhaps you realize that you asked Mathematica to do the wrong thing. Or ...

DialogReturn[expr] closes a dialog window, returning the expression expr from the dialog.DialogReturn[] closes a dialog window, returning Null.

SystemDialogInput["type"] brings up an interactive system dialog and returns the value chosen in the dialog. SystemDialogInput["type", init] uses init as the initial setting ...

MonitorLM gives information on the total number of licenses available and checked out, the fully qualified domain name and username of those who have them checked out, and so ...

Widget["FontChooser"] provides a panel for making a font selection based on a name, style, and size.

DirectoryQ["name"] gives True if the directory with the specified name exists, and gives False otherwise.

Editable is an option for displayed objects, cells, and notebooks that specifies whether their contents can be edited interactively using the front end.

FileExistsQ["name"] gives True if the file with the specified name exists, and gives False otherwise.