The text editor sam.

Sam is an interactive multi-file text editor intended for bitmap displays. A textual command language supplements the mouse-driven, cut-and-paste interface to make complex or repetitive editing tasks easy to specify. The language is characterized by the composition of regular expressions to describe the structure of the text being modified. The treatment of files as a database, with changes logged as atomic transactions, rationalizes the implementation and makes a general 'undo' mechanism straightforward.