I've specifically mentioned GIF, MP3 protected by patents. MP3 patents encoding-decoding. > GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless

I've specifically mentioned GIF, MP3 protected by patents. MP3 patents encoding-decoding. > GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. This compression technique was patented in 1985. [1] x86 protected by patents: > Partly. For some advanced features, x86 may require license from Intel; x86-64 may require an additional license from AMD. The 80486 processor has been on the market for more than 20 years and so cannot be subject to patent claims. The pre-586 subset of the x86 architecture is therefore fully open. [2] One can build/emulate 80486 but not x86-64, SSE, AVX, VT-x etc. [1] https://en.wikipedia.org/wiki/GIF https://en.wikipedia.org/wiki/GIF [2] https://en.wikipedia.org/wiki/X86 https://en.wikipedia.org/wiki/X86