Complete Amino. -> multiplier of productivity for SDK development, to not have to think about protobuf at all. Use "genproto" to even auto-generate proto3 for encoding/decoding optimization through protoc. // MISSION: be the basis for improving the encoding standard from proto3, because proto3 length-prefixing is slow, and we need "proto4" or "amino2". // LOOK at the auto-generated proto files! https://github.com/gnolang/gno/blob/master/pkgs/bft/consensus/types/cstypes.proto for example. // There was work to remove this from the CosmosSDK because Amino wasn't ready, but now that it is, it makes sense to incorporate it into Tendermint2.
Remove EvidenceReactor, Evidence, Violation -> we need to make it easy to create alt mempool reactors. We "kill two birds with one stone" by implementing evidence as a first-class mempool lane. The authors of "ABCI++" have a different set of problems to solve, so we should do both! Tendermint++ and Tendermint2.
Fix address size to 20 bytes -> 160 is sufficient, and fixing it brings optimizations.
General versionset system for handshake negotiation. -> So Tendermint2 can be used as basis for other p2p applications.
EventBus -> EventSwitch. -> For indexing, use an external system. This keeps Tendermint2 minimal, allowing integration with plugin modules, without having any internal implementation at all. EventSwitch is also simpler, and synchronous, and this keeps the Tendermint tests deterministic. There is no performance need to do anything else than keep the Tendermint protocol synchronous. (If there is, because of massive validator numbers for whatever reason, then it should be a fork of Tendermint with a unique & distinct name, and would be under the same taxonomy of Tendermint).
Fix nondeterminism in consensus tests -> in relation to the above.
Add "MaxDataBytes" for total tx data size limitation. -> The previous way of limiting the total block size may result in unexpected behavior with changes in validator size. We should err to allocate room for each module seperately, to ensure availability.
Remove external dependencies like prometheus. -> Any metrics and events should be plugged in through the implementation of interfaces. This may involve picking out the client logic from prometheus, but even if so it would be forked into Tendermint2 and be audited like anything else.
General consensus/WAL -> a WAL is useful enough to warrant being a re-usable module.
Remove GRPC -> GRPC support should be plugged in (say in a GRPC fork of Tendermint2), so alternative RPC protocols can likewise be. Tendermint2 aims to be independent of the Protobuf stack so that it can retain freedom for improving its codec.
Remove dependency on viper/cobra -> I have tried to strip out what we don't use of viper/cobra for minimalism, but could not; and viper/cobra is one prime target for malware to be introduced. Rather than audit viper/cobra, Tendermint2 implements a cli convention for Go-structure-based flags and cli; so if you still want to use viper/cobra you can do so by translating flags to an options struct.
Question: Which projects use ABCI sockets besides CosmosSDK derived chains?
First, we create a multi-organizational team for Tendermint2 & TendermintCore/++ development. We will maintain a fork of the Tendermint++ repo and suggest changes upstream based on our work on Tendermint2, while also porting necessary fixes from Tendermint++ over to Tendermint2.
We will also reach out to ecosystem partners and survey and create a directory/taxonomy for Tendermint and CosmosSDK derivatives and manage a forum for interfork collaboration.
Ideally, Tendermint2 and TendermintCore/++ merge into one.
Either make a PR to Gaia/CosmosSDK/TendermintCore to be like Tendermint2, or make a PR to Tendermint2 to import a feature or fix of TendermintCore.