Lista de segundas caspas propuestas

Ark

https://arkdev.info/
https://twitter.com/somsenruben/status/1726393664757174677
https://arkdev.info/roadmap/
https://ark.vulpem.com/

Bancos privados antiguos emitían billetes a cambio de depósitos de oro, que eran canjeables por oro en cualquier momento.
Estos billetes dependían de la solidez del banco; si el banco quebraba, los billetes perdían su valor.
Alice deposita Bitcoin en un servidor digital y recibe un cheque digital con fecha de caducidad.
Para mantener su cheque válido y su fondo seguro, Alice debe interactuar con el servidor al menos una vez al mes.
El cheque puede usarse para pagos dentro del mismo banco digital y puede ser canjeado por Bitcoin antes de su expiración.
Si el banco digital desaparece, los usuarios pueden recuperar su "oro digital" a través del blockchain de Bitcoin, garantizando la seguridad y accesibilidad del fondo

BitVM https://bitvm.org/bitvm.pdf

BitVM is a computing paradigm to express Turing-complete Bitcoin contracts. This requires no changes to the network’s consensus rules. Rather than executing computations on Bitcoin, they are merely verified, similarly to optimistic rollups. A prover makes a claim that a given function evaluates for some particular inputs to some specific output. If that claim is false, then the verifier can perform a succinct fraud proof and punish the prover. Using this mechanism, any computable function can be verified on Bitcoin. Committing to a large program in a Taproot address requires significant amounts of off-chain computation and communication, however the resulting on-chain footprint is minimal. As long as both parties collaborate, they can perform arbitrarily complex, stateful off-chain computation, without leaving any trace in the chain. On-chain execution is required only in case of a dispute.

Drivechains bip300

Drivechains

Mercury layer

https://bitcoinmagazine.com/technical/mercury-layer-a-massive-improvement-on-statechains
https://bitcoinmagazine.com/technical/a-new-privacy-tool-for-bitcoin
https://github.com/commerceblock/mercurylayer/tree/dev/docs