Topic summary
Second-source

Extracted from the Wikipedia article Second source.
Examples
Intel licensed AMD to second-source Intel microprocessors such as the 8086 and its related support components. This second-source agreement is particularly famous for leading to much litigation between the two parties. The agreement gave AMD the rights to second-source later Intel parts, but Intel refused to provide the masks for the 386 to AMD. AMD reverse-engineered the 386, and Intel then claimed that AMD's license to the 386 microcode only allowed AMD to "use" the microcode but not to sell products incorporating it. The courts eventually decided in favor of AMD.