I think an even more stupid example was the xor cursor technique that was locked up by CadTrac, (later Quantel) and forced a rewrite of parts of X, and the Amiga.<p><a href="https:&#x2F;&#x2F;plus.google.com&#x2F;+RayCromwell&#x2F;posts&#x2F;dbipY1GJoGv" rel="nofollow">https:&#x2F;&#x2F;plus.google.com&#x2F;+RayCromwell&#x2F;posts&#x2F;dbipY1GJoGv</a>