3/ Cheetah uses the same underlying number system as Nockchain's proofs. That lets its signature maths fit those proofs directly. Using a different number system would require extra arithmetic to express the same checks.

3/ Qubitcoin approaches the field through mining. Its public implementation runs quantum calculations in software on ordinary GPUs. Picture a software model of a quantum circuit, with miners competing to calculate it efficiently for block rewards.

3/ Each agent keeps developing its own code. The tool runs benchmarks to score each attempt, while a shared server tracks results and passes ideas between agents. The docs explicitly say peer code is for study, rather than replacing your own program.

3/ The fund's spending rule requires three of four designated signatures. One signer can't release the money alone. The code also checks that each eligible block pays the exact fund share, so a miner can't quietly skip the allocation.

3/ Each task has its own starting point and can be switched on at a chosen block. The practical idea is to introduce a new computational challenge while keeping the same chain. Research could gain another route to mining rewards without needing a new currency.