Because relevant US and EU software copyright law permits reverse engineering as "fair use", blanket contractual prohibitions on reverse engineering (eg, "Licensee will not reverse engineer, decompile, decode, decrypt, disassemble, or in any way derive source code from, the Licensed Software") are not likely to be enforced. These jurisdictions countenance reverse engineering as fair use if conducted in order to achieve interoperability between the licensed software and independently created software.
