Design-by-Contract is protected by various business restrictions so it has nobody but itself to blame for its unpopularity What's this about? Some patent or so

Design-by-Contract is protected by various business restrictions so it has nobody but itself to blame for its unpopularity What's this about? Some patent or something? I'd guess this is a reference to Bertrand Meyer's company. Since I learned DbC from Liskov & Guttag's excellent book, which came out before Meyer's, I never had much reason to look into Meyer or Eiffel even though they became practically identified with DbC.