Pros of go-ethereum

• Public, permissionless blockchain with a large, active community
• Native cryptocurrency (Ether) and robust support for smart contracts
• Widely adopted and battle-tested in production environments

Cons of go-ethereum

• Lower transaction throughput compared to Fabric
• Higher energy consumption due to Proof-of-Work consensus (pre-Merge)
• Less flexibility in terms of privacy and access control

Code Comparison

go-ethereum (Solidity smart contract):

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 private storedData;

    function set(uint256 x) public {
        storedData = x;
    }

    function get() public view returns (uint256) {
        return storedData;
    }
}

Fabric (Chaincode in Go):

package main

import (
    "fmt"
    "github.com/hyperledger/fabric-contract-api-go/contractapi"
)

type SimpleAsset struct {
    contractapi.Contract
}

func (t *SimpleAsset) Set(ctx contractapi.TransactionContextInterface, key string, value string) error {
    return ctx.GetStub().PutState(key, []byte(value))
}

func (t *SimpleAsset) Get(ctx contractapi.TransactionContextInterface, key string) (string, error) {
    value, err := ctx.GetStub().GetState(key)
    if err != nil {
        return "", fmt.Errorf("failed to read from world state: %v", err)
    }
    return string(value), nil
}

Pros of Corda

• Designed specifically for financial services, with built-in privacy and regulatory compliance features
• Supports multiple consensus mechanisms, allowing for more flexibility in network design
• Uses a unique "flow framework" for coordinating complex, multi-party transactions

Cons of Corda

• Smaller community and ecosystem compared to Fabric
• Steeper learning curve due to its specialized nature and use of Kotlin
• Limited support for smart contracts written in languages other than Java or Kotlin

Code Comparison

Fabric (Chaincode in Go):

func (s *SmartContract) CreateAsset(ctx contractapi.TransactionContextInterface, id string, value int) error {
    asset := Asset{ID: id, Value: value}
    assetJSON, err := json.Marshal(asset)
    if err != nil {
        return err
    }
    return ctx.GetStub().PutState(id, assetJSON)
}

Corda (Flow in Kotlin):

@Suspendable
override fun call(): SignedTransaction {
    val notary = serviceHub.networkMapCache.notaryIdentities.first()
    val txBuilder = TransactionBuilder(notary)
    .addOutputState(AssetState(value, ourIdentity), AssetContract.ID)
    .addCommand(AssetContract.Commands.Create(), ourIdentity.owningKey)
    val signedTx = serviceHub.signInitialTransaction(txBuilder)
    return subFlow(FinalityFlow(signedTx, listOf()))
}

Pros of Quorum

• Built on Ethereum, leveraging its extensive ecosystem and tooling
• Supports both public and private transactions within the same network
• Offers multiple consensus mechanisms (RAFT, IBFT, Clique)

Cons of Quorum

• Less modular architecture compared to Fabric
• Limited support for complex smart contract languages beyond Solidity
• Smaller community and fewer enterprise-grade deployments

Code Comparison

Fabric (Chaincode in Go):

func (s *SmartContract) CreateAsset(ctx contractapi.TransactionContextInterface, id string, value int) error {
    asset := Asset{ID: id, Value: value}
    assetJSON, err := json.Marshal(asset)
    if err != nil {
        return err
    }
    return ctx.GetStub().PutState(id, assetJSON)
}

Quorum (Smart Contract in Solidity):

pragma solidity ^0.8.0;

contract AssetManager {
    mapping(string => uint256) private assets;

    function createAsset(string memory id, uint256 value) public {
        assets[id] = value;
    }
}

Both Fabric and Quorum are enterprise-focused blockchain platforms, but they differ in their approach and underlying technology. Fabric offers a more modular and flexible architecture, while Quorum builds upon the Ethereum ecosystem. The choice between them depends on specific project requirements and existing technology stacks.

Pros of Substrate

• More flexible and customizable blockchain framework
• Easier to develop and deploy custom blockchains
• Better suited for building interoperable blockchain networks

Cons of Substrate

• Steeper learning curve due to its complexity
• Less mature ecosystem compared to Fabric
• Fewer enterprise-focused features out of the box

Code Comparison

Substrate (Rust):

#[pallet::weight(10_000)]
pub fn do_something(origin: OriginFor<T>, something: u32) -> DispatchResult {
    let who = ensure_signed(origin)?;
    <Something<T>>::put(something);
    Self::deposit_event(Event::SomethingStored(something, who));
    Ok(())
}

Fabric (Go):

func (s *SmartContract) DoSomething(ctx contractapi.TransactionContextInterface, something string) error {
    err := ctx.GetStub().PutState("something", []byte(something))
    if err != nil {
        return fmt.Errorf("failed to put to world state: %v", err)
    }
    return nil
}

The code snippets demonstrate the different approaches to implementing smart contract logic in Substrate and Fabric. Substrate uses Rust and a more declarative style, while Fabric uses Go and a more imperative approach.

Pros of EOS

• Higher transaction throughput and scalability
• More user-friendly for developers with WebAssembly support
• Faster block confirmation times (0.5 seconds)

Cons of EOS

• More centralized governance model
• Limited privacy features compared to Fabric
• Potential for network congestion during high-demand periods

Code Comparison

EOS (C++):

#include <eosio/eosio.hpp>

class [[eosio::contract]] hello : public eosio::contract {
public:
    [[eosio::action]]
    void hi(name user) {
        print("Hello, ", user);
    }
};

Fabric (Go):

func (s *SmartContract) Hello(ctx contractapi.TransactionContextInterface, name string) error {
    return ctx.GetStub().PutState("greeting", []byte("Hello, "+name))
}

Key Differences

• EOS uses C++ for smart contracts, while Fabric supports multiple languages (Go, Java, JavaScript)
• EOS focuses on high-performance public blockchains, whereas Fabric is designed for permissioned enterprise networks
• EOS uses a Delegated Proof-of-Stake consensus mechanism, while Fabric offers pluggable consensus protocols

Use Cases

• EOS: Decentralized applications (dApps) with high transaction volumes, gaming, social media
• Fabric: Supply chain management, financial services, healthcare data sharing

Pros of Tendermint

• Simpler architecture and easier to understand
• Better performance and scalability for high-throughput applications
• More flexible consensus mechanism, allowing for various voting power distributions

Cons of Tendermint

• Less mature ecosystem and enterprise adoption compared to Fabric
• Fewer built-in privacy features and permissioning options
• Limited smart contract support out of the box

Code Comparison

Tendermint (Go):

func (app *KVStoreApplication) DeliverTx(req abci.RequestDeliverTx) abci.ResponseDeliverTx {
    key, value := req.Tx[:32], req.Tx[32:]
    app.state.Set(key, value)
    return abci.ResponseDeliverTx{Code: 0}
}

Fabric (Go):

func (s *SmartContract) Invoke(ctx contractapi.TransactionContextInterface) error {
    _, args := ctx.GetStub().GetFunctionAndParameters()
    err := ctx.GetStub().PutState(args[0], []byte(args[1]))
    return err
}

Both examples show simple key-value storage operations, but Fabric's approach is more abstracted and integrated with its chaincode concept, while Tendermint's is more direct and lower-level.