In recent years, many developers have been discussing the OP_CAT mechanism. Until January this year, the Quantum Cats team significantly increased the discussion of the OP_CAT BIP topic. The co-founder of Taproot Wizard @ercwl proposed that OP_CAT is actually one of the building blocks of zkrollup on Bitcoin. The restart will actually take some time, including technical details, Bitcoin security and stability, and community consensus. @ProtocolCAT has received a lot of comments and attention from the Bitcoin ecosystem at home and abroad as soon as it went online. It was initially built on Fractal, but in the final analysis, what it does is for the development of OP_CAT, just like Quantum Cats.