Another day, another lawsuit. Apple is being sued by Data Engine Technologies for patent infringement, reports “The Mac Observer ( The suit claims Apple’s Numbers spreadsheet software violates its patent (number 5463724) for an “improved spreadsheet interface with user-familiar objects.”

The lawsuit was filed in U.S. District Court in the Eastern District of Texas, Tyler Division. The summary of the patent in question reads:

“An electronic spreadsheet system of the present invention includes a notebook interface having a plurality of notebook pages, each of which may contain a spread of information cells, or other desired page type (e.g., Graphs page). Methods are provided for rapidly accessing and processing information on the different pages, including displaying a plurality of page identifiers for selecting individual pages, and further including a preferred syntax for referencing information. Additional methods are provided for editing cells and blocks of cells.”