The Value of Cryptocurrencies in Supporting Human Rights
Executing with subtraction in the Infinite Garden
Ethereum in 30 minutes
Publisher’s Denial of Digital Ownership vs Decentralization
Watch / Ethereum 2 Network Spec and Structure
Speaker: Zahary Karadjov
Event: Devcon 5
Date: Oct 2019
A Modest Proposal for Ethereum 2.0
Vitalik Buterin gives his talk titled, "A Modest Proposal for Ethereum 2.0"
Ethereum 2.0 randomness
Justin Drake talks about the randomness behind Ethereum 2.0 using a Verifiable Delay Function.
The Case for Proof-of-Stake
Emin Gün Sirer gives an overview of blockchain & how we got here, and makes the case for Proof-of-Stake.
Emin Gün Sirer
A Conservative Approach to a Radical Roadmap
The current Ethereum 2.0 roadmap is doing a lot of great work on many fronts such as research on VDFs, data availability proofs, and multi-execution environments. However, as an active observer of the Ethereum 2.0 roadmap development over the past 2 years, I am concerned with some of the choices in roadmap strategy, particularly its approach to radically transforming a network with over $30B of value and hundreds of applications depending on it. In this talk, I will present an alternative, more conservative view of how to approach the Ethereum 2.0 roadmap. Some of the topics covered will include: - Radical vs Conservative technological upgrade paths. - We should use Ethereum 1.x as the beacon chain instead of launching a new beacon chain. - Proof of Stake is highly experimental. We should test Proof of Stake on shards before using it on the beacon chain. - Why requiring a 1-way peg burn of ETH to stake is scary. - Learnings from 3 months of Proof of Stake on Cosmos - Why we NEED delegation *in-protocol* - Why sharding doesn't solve social scalability.
An Examination of the Evolution of Staking and Validators
Ethereum 2.0 Phase Zero is rapidly approaching. Extensive research has been conducted on Proof-of-Stake, along with multiple tests and debates to discuss the economics of how this transition will play out. However, there are a few real world data points worth observing in order to understand how Ethereum 2.0 staking and validator markets will play out. stake.fish has been in operations for a year supporting projects like Cosmos, Tezos, and Loom Network. We would love to share how these staking projects evolved along with the stakeholders around them. We can't wait for Devcon 5 and for Ethereum 2.0 :)
Jun Soo JK Kim
Building Ethereum 2.0 On Substrate
Wei Tang presents Building Ethereum 2.0 on Substrate.
Demystifying libp2p gossipsub: a scalable and extensible p2p gossip protocol
ETH2.0 is evaluating libp2p gossipsub as a decentralized, peer-to-peer publish/subscribe mechanism for validators, proposers and attesters to quickly disseminate data throughout the entire network. This talk covers the technical design, tradeoffs and functionality of gossipsub, aiming to deliver foundational knowledge to everyone interested in learning more about this potential building block of the ETH2.0 network. Gossipsub was incubated in the libp2p project as a replacement for the naïve floodsub pubsub router (which simply broadcasts messages to all peers we know are interested in a topic). It maintains stable reciprocal meshes via explicit link grafting, while preserving random gossip to disseminate metadata, and to provide cues to aid message deliverability. It also features a piggybacking algorithm to minimise the overhead of control messages; allows developers to attach custom per-topic validator functions; and more. Come to learn more about how gossipsub works, and to hear about the state of the art of p2p pubsub protocols!
Eth 2.0 light clients: How light is light?
Ethereum 2.0 has been designed from the ground up to be friendly for "light clients" - blockchain clients requiring vastly reduced computational resources that can easily be run in the browser, in embedded devices, and even inside other blockchains! We discuss how light clients work in Eth2.0, why light clients are lighter than full nodes, and get to the bottom of just how "light" these clients can be.
Greg Markou, Cayman Nava
Eth 2.0 Minimal Execution AMA
A fishbowl style conversation with lead researchers and passionate contributors to Eth 2.0, but allowing anyone from the audience to stand up and lead a topic. The intent is to discuss certain key topics around the design of the Eth 2.0 shards and how they can be used by the everyday dapp developer. This session aims to bring everyone interested in Eth 2.0 execution to a friendly discussion.
Alex Beregszaszi, Casey Detrio
Eth 2.0 on a Pi
Throughout the years, one of the main complaints of blockchains and Ethereum has been how much energy it consumes to secure transactions. Thus, blockchain is often associated with energy waste in mainstream views. Eth 2.0 with its proof-of-stake consensus promises significantly improved energy consumption. It also brings back validation power to common hardware while proof-of-work increasingly requires interested parties to invest in specialized hardware, space and location. Let's dive together to see if the beacon chain holds those promises and run it on one of the most accessible hardware: the Raspberry Pi.
Eth 2.0; tldr
High level overview of the work that has gone into Ethereum 2.0 since last devcon, the major milestones achieved, the landscape of research, and where we're going in the next 12 months. This serves as an overview talk for the track to get devcon attendees acquainted with the space in general and ground them for the range of more technical talks throughout the conference.
Eth2 Collaboration Culture
We discuss the trend of collaboration within the blockchain industry, presenting specific examples from Ethereum 2.0 R&D. This talk will highlight the hard Eth2 problems that are being tackled with other blockchains, academic teams and companies.
Eth2 Phase 0 Technical Deep Dive
Seminar style deep-dive on phase 0 of Ethereum 2.0. Content includes explanations, diagrams, Q&A, etc. Session will open with a high level overview, followed by a deep-dive explanation and analysis of the various components of the system ultimately showing how all of the pieces fit together. Various researchers and developers to present on sub-topics related to their expertise.
Danny Ryan, Alex Stokes, Chihcheng Liang
Eth2.0 Client Panel
Panel discussing the short-term future for Eth 2.0 clients.
The Ethereum Magicians discuss Ethereum 2.0
Ethereum 2.0 Phase 1&2 Developer Experience
In this breakout session, we would invite some prominent Dapp developers to discuss the developer experience with Ethereum 2.0 researchers and client implementers. The goals of this session: Phase 1 will enable some layer 2 scaling framework to be much more useful! What would the developers need to know? And what are the edge-cutting tools they can start to dig?Till today, the most promising Phase 2 proposal is the execution environment abstraction by Vitalik Buterin (https://notes.ethereum.org/s/Bkoaj4xpN). While this scheme would only add minor cost to migrate the existed Dapp, it would be great to understand the requirements from the perspective of developers.What's the user experience regarding cross-shard transactions?To get some more concrete ideas of the Eth2 tooling we will need.
Jacek Sieka, Hsiao-Wei Wang
Ethereum 2.0 Trustless Staking Pools
One of the goals of the Ethereum 2.0 protocol is to allow for trustless staking pools. The main difficulty that had to be overcome to achieve this was the proof of custody construction, which we specifically changed to use a very MPC-friendly cryptographic primitive, the Legendre symbol.
Carl Beekhuizen, Dankrad Feist
Ethereum Roadmap 2020 Eth1 to Eth2 Transition
The Ethereum Magicians give an update and a Roadap for Ethereum in 2020 and beyond, looking ahead to the transition to Eth 2.0
Handel: Practical Multi-Signature Aggregation for Large Byzantine Committees
We present Handel, a Byzantine fault tolerant aggregation protocol that allows for the quick aggregation of cryptographic signatures over a WAN. Handel has logarithmic time and polylogarithmic network complexity and needs minimal computing resources. We implemented Handel as an open source Go library with a flexible design to support any associative and commutative aggregation function. We tested Handel with a BLS multi-signature scheme for BN256 on 2000 AWS instances running two nodes per instance and located in 10 AWS regions. The 4000 signatures are aggregated in less than 900 milliseconds with an average per-node communication cost of 56KB. This work can be used to improve Ethereum 2's latency to finality.
Olivier Bégassat, Nicolas Gailly, Blazej Kolad, Nicolas Liochon
Interblockchain Communication & Interchain Topology
The interblockchain community protocol will faciliate permissionless interoperation between smart contracts on Ethereum 1.0/1.x & Ethereum 2.0, Cosmos zones, Polkadot parachains, Bitcoin & more. The first half of this talk presents the protocol construction, notes security properties & consensus requirements, explains the message channel interface exposed to smart contracts & modules, and discusses special techniques for bridging Nakamoto proof-of-work consensus blockchains such as Ethereum 1.0/1.x to chains with finality. The second half embarks on a speculative exploration of what the future topology of interconnected blockchains might look like: what economic constraints might shape cross-chain design choices, what kinds of applications might most benefit from cross-chain logic, and what shared ecosystem standards might most effectively facilitate positive-sum interoperation, with particular attention to integration into the Ethereum 2.0 specification process.
libp2p ecosystem: what’s up and what’s next
The libp2p networking stack is becoming a foundational element in many decentralized systems (including ETH2.0). In this session, we'd like to: walk the audience through the current state of the ecosystem, and the 7+ language implementations.explain the toughest problems the core team and community is currently researching and hacking on, e.g. decentralized NAT traversal, slimming down protocols, censorship and deep packet inspection, DHT scaling, traffic shaping, resource control, etc.present what features, subsystems, protocols and redesigns are coming next in libp2p.call out for help and participation in areas where input, feedback and help from contributors is appreciated.Join us, and let's advance the state of the art of p2p networks together!
Load Balancing in Eth2
Joe Delong from Pegasys gives an overview of the Artemis Architecture.
Networking in ETH2.0
The Whiteblock team has been working on several ETH 2.0 related projects over the past year. These projects include: An analysis of Libp2p’s gossipsub in collaboration with the ETH Research team, The development of protocol-specific tooling and utilities, constituting the basis of the ETH2.0 test runner (developed in collaboration with Moloch DAO and provided to the community as open source software), as well as Contributing to the specification for the currently implemented wire protocol.
I propose to deliver a 15-minute presentation, consisting of two parts: A brief 7 minute overview of the tools and protocols, such as Hobbits, a lightweight wire protocol designed to allow Eth2.0 clients to exchange information, developed to accelerate the testing of Eth 2.0 client; and an 8 minute summary of Whiteblock’s most recent analyses on Eth2.0 networking protocols such as libp2p.
Antoine Toulme, Rene Nayman
Michael Sproul from Sigma Prime discusses Optimizing Eth2.
p2p - where are we with the ecosystem and how to push it forward?
p2p and Ethereum need each other a lot in order to bring decentralized future, but we're not working together very well. Leaders of p2p projects and core blockchain/dapp developers in the same room to build bridges and align plans on day0.Blockchain/dapp people don't know too much about p2p projects and don't have access to p2p stack that they need to build real decentralized applications. p2p people can't navigate blockchain ecosystem, don't know what's needed, don't have access to funding.We've set out to fix all of this in 2019. 3 phases:1.p2p Ecosystem report. Directory and assessment of what works right now.2.p2p ecosystem position paper. How to design p2p ecosystem from first principles and how should we get there, what are the priorities for reasearch/funding.3.p2p infrastructure DAO. Experts from both p2p and Ethereum allocating grants together. $400k already committed to grants. This breakout session would briefly present findings of the p2p ecosystem report, but would focus on designing perfect p2p ecosystem that would make deliver everything needed to make Ethereum ecosystem happy. We're also submitting a 20-minute talk proposal "State of p2p" where leaders of key p2p projects we would present learnings from this workshop on day1.
Polkadot's Data Availability and Validity Scheme
How can we make blockchains secure at scale? We suggest a data availabilitty and validity scheme that make sharding efficient in terms of the number of validators and validating resources. We first describe the Polkadot data availability and validity scheme and consider its applicability to other sharded systems (e.g. ETH2.0). In Polkadot we tie an erasure coding data availability scheme with consensus, where we can not finalise an unavailable block. Moreover, reports of unavailability or invalidity trigger extra checks. The aim is that, with high probability, we do not finalise an unavailable or invalid block provided that there are enough honest actors to report. The key advantage of this scheme is that we need fewer validating actors per shard and in turn less total computational and especially networking resources. This softens the trade-off between scalability and security.
Putting Eth2.0 To Work
There is much excitement around Ethereum 2.0 but given the fast pace of the project it can be hard to keep up. The relationship between today's Ethereum and the new system can be murky: does eth2.0 replace eth1.0? And where does eth1.x fit in?This talk answers these questions by sketching the lesser known ways eth2.0 can directly benefit Ethereum 1.x. The two systems in fact complement each other as each phase of eth2.0 paves the way for tangible benefits to the network we all know and love. With Phase 0, we can upgrade Ethereum with the finality gadget, leveraging the proof-of-stake consensus to provide better security for the existing chain. With Phase 1, the proof-of-work chain can use the data-only shards to enhance the scalability of L2 solutions like zk-rollup and Plasma. With Phase 2, we can bring existing dApps into the realm of highly scalable smart contracts on shards with an upgraded virtual machine.Participants will gain a better understanding of the many ways eth2.0 can help scalability in the near term and onward into the future. While the journey there may be dynamic and winding, it is clear that the future of Ethereum is bright.
The CBC Casper Roadmap
The CBC Casper roadmap is a plan to implement Proof-of-Stake and Sharding for Ethereum using “correct-by-construction” (CBC) software design methodology. This talk will share new CBC Casper research, including specifications for light clients, liveness and sharding. It will include updates on formal verification and engineering efforts, and a roadmap for (eventual) release.
The Nuts and Bolts of Cross-Chain Communication
Throughout the past years, research into facilitating trustless cross-chain communication has resulted in the proposal of numerous concepts and mechanisms. However, to this date, the work is scattered across blog posts, scientific papers and code. The goal of this workshop is to provide an overview of the fundamentals of cross-chain communication, especially in cross-ledger exchanges and sharding. Our goal is that participants understand the differences between trusted/custodial and trustless/non-custodial approaches, and the challenges we face today.We split the workshop into 2 parts:Theory: Overview: motivation, challenges and different approaches and use cases. Focus on (i) cross-ledger exchanges (atomic swaps and cryptocurrency-backed assets), and (ii) sharding, (different proposals and how they handle cross-shard transfers). Two technical deep dives: chain relays and data availability / fraud proofsPractice: Interactive coding workshop: participants build their own Bitcoin chain relay. We provide Solidity code with missing code snippets and help participants find the correct solution. In the end, we present our example implementation and discuss the approaches found by workshop participants. People who do not wish to code or are unfamiliar with Solidity: interactive walk-though for the BTC Relay implementation + detailed discussion of possible attacks to foster adversarial thinking.
Mustafa Al-Bassam, Dominik Harz, Alexei Zamyatin
Toward Ethereum 2.0 Sharding Universe
Ethereum 2.0 beacon chain has introduced the basic structure of the sharded networks. This presentation would discuss the current research on the sharded network topology and the strategies of the Ethereum 2.0 clients for the future shard chains.
Towards Eth2 Developer Tooling
Gregory Markou gives his talk on Eth2 Developer Tooling.
Weak Subjectivity and Eth 2.0 Sync
Hsiu-Ping Lin speaks on Weak Subjectivity and Eth 2.0.
When 1 Million Eth Devs?
The Ethereum ecosystem has achieved a lot over the past year with respect to core development, adoption, defi, and improving scalability. Ethereum’s main advantage in the blockchain space is the community of developers that continues to build and grow the network. Joe Lubin’s talk will discuss the state of development on the Ethereum blockchain, set some benchmarks for the next year, and propose a common goal: When 1 Million ETH Devs?
Why Dapp Users will Hate Cross-Shard Communication (and what you can do about it)
ETH2 is approaching, and initial indications are that substantially all dapp experiences will suffer. Some problems may be addressed with significant changes to design and development processes, but several tradeoffs are unavoidable without sacrificing scale, security, or decentralization. For example, essentially all popular dapps rely on the fungibility of Ether in a managed pool (e.g. Uniswap, Augur, Maker). In a sharded ecosystem, Ether is meaningfully non-fungible across shards, and users will bear monetary and management costs as a result.This talk will give an overview of cross-shard communication strategies and discuss their impact on developer and user experience. These include merged consensus, shard relays, consensus introspection, and credit markets. For each mechanism, we'll discuss expected impact on user experience metrics like execution time, transaction outcome, and price slippage.The talk is not all bad news. We've discovered some elegant new approaches that give dapps a variety of communication choices. The last section of the talk will discuss specific communication strategies that are amenable to specifi
A Breakdown of Ethereum Supply Distribution Since Genesis
As Ethereum looks ahead to its transition to a fully to a proof-of-stake consensus protocol, the topic of Ethereum’s supply distribution matters more than ever to network stakeholders. This is because under PoS, the amount of ETH users control directly determines how much influence they can have over the network’s consensus building process and the amount of rewards they can earn from staking. This talk dives into how distributed ETH supply on Ethereum has become over the last 7 years.
Beyond Stake: Implementing Diversity Policies on PoS
We look at the challenges of implementing various diversity-improving policies on a PoS network. Economic (dis)incentivization is a popular approach, but can be undermined by non-standard miner economics such as (cross-domain) MEV or derivatives on incentivization. As an alternative, we outline an approach to include diversity support into the consensus level without requiring changing the basic functionality of the protocol by adapting the concept of general adversary structures.
Can’t Someone Else Do It!? Shifting Behaviors in Ethereum Network Participation
Decentralization is touted to be at the core of the Ethereum ecosystem and community. Yet we continue to operate in a world of end users trained and programmed not to think about any of the infrastructure services they use, how they run, how secure they are, and how they are managed. The community continues to operate with the mantra of Web 2.0 where someone else can handle it. It is up to us to help shift user behaviors and mental models around what it takes to truly participate in the network.
Client Diversity Matters: Thinking Independently, Together
There is an ongoing conversation about the increased centralization of the Ethereum ecosystem following the migration to Proof of Stake. Clients deployed, nodes location, hosting services as well as liquid staking providers that have significant relevance that could potentially reduce the resilience of the network as a whole. We will dive into the state of the network post-merge and share specific actions related to how we can collaborate for a better outcome for the Network.
Does it Make Sense to Aggregate and Average feeReceipent Rewards Using a Smoothing Pool?
This talk presents a statistical model and python code that can be used to model feeRecipient tips using a set of binomial, Gaussian, and Bayesian modeling techniques. We will explore if the ideal of pooling these fees, similar to how POW miners have been pooling their hash power, makes sense for Ethereum validators. We will present the results of modeling one such feeReceipent pooling contract to determine if such a model adds value to other validating Ethereum Node operators.
Everything a Solo Staker Should Know for the Next Phase of Ethereum
Solo stakers have a lot on their plate. Keeping up with every single change, how it will affect them and what steps they need to take to ensure their operation runs smoothly is a full time job! In this talk we are going to detail very clearly everything that they should be doing, everything that's coming, what tools and projects are coming to the rescue and what they are expected to do.
Formal Specification and Verification of the Distributed Validator Technology protocol
In this talk, we present our work on formally specifying and verifying the Distributed Validator Technology (DVT) protocol, using the verification-ready programming language Dafny, to ensure that the DVT protocol behaves as expected. You will learn how to read the formal specification, how to use it to write your own implementation of the protocol, what properties we have formally proven to be guaranteed by the protocol and what the future directions of the DVT protocol and our work are.
How to Build a Decentralized Ethereum Liquid Staking Protocol?
Liquid staked Ethereum is a reliable source of yield and is fast becoming a key primitive in DeFi. Come hear from Rocket Pool about their experience designing a decentralized Ethereum liquid staking protocol. How do you create a decentralized protocol for staking? What are some of the design trade offs in token design? What tools are available today? What challenges exist due to current L1 structures? What opportunities exist in future upgrades?
How to Design DVT While Ensuring Non-Correlation
The proof of stake Ethereum specs are designed to encourage decentralization by punishing centralization. In this session, we will discuss how to design Distributed Validator Technology in a way that minimizes correlation risk by using design choices across distributed key generation, middleware, networking topology, and versioning. We'll also describe why creating a trust-minimized, non-custodial, and non-correlated architecture is the most healthy way to enable multi-operator staking.
Collin Myers, Oisín Kyne
How to Run a Validator From Zero on Resource-Constrained and Low Powered Devices
Our main goal is to contribute to the network decentralization by making it easier and affordable for regular users to run nodes (and staking) on resource-constrained devices as well as helping to test the next major Ethereum upgrade (The Merge).
In this workshop we will show from scratch how to install and set up an Ethereum validator node, from running the Execution Layer + Consensus Layer combo to creating the keys and setup for the validator in order to get it up and running.
"It's 10pm, do you know where your mnemonic is?"
Many stakers set up their validators nearly two years ago, and will soon need to revisit them to obtain the rewards they have earned since. This panel provides a refresher for what stakers did, and why they did it. It discusses protecting mnemonics and keys, and what can be done if they are misplaced or compromised. Bringing together experts on validating key creation, protection and use, this is a wide-ranging discussion that will be useful for all stakers and potential stakers.
Adrian Sutton, Oisín Kyne, Paul Hauner, Vasiliy Shapovalov
Launch Your Own Validator Node
taking someone through every step of provisioning their own nodes. Go from independent 1 server deployments to multi-server deployments in the workshop. Attendees will be able to spin up and manage their own nodes with easy to use open source software.
Like a Kindergeburtstag - Ethereum Node in under 3 minutes with Stereum
Stereum is a tool to manage the process of setting up & maintaining an Ethereum node for the user with a heavy focus on self sovereignty, privacy and flexibility. With Stereum you are capable of setting a node up in under 3 minutes. Around Bogota we hope to have finished our full release version (currently in beta - https://github.com/stereum-dev/ethereum-node/milestones?state=closed) and would like to talk about the development, the challenges and why a node is valuable infrastrucutre
[Panel] The Staking Economy: From Monolith to Modularity
The staking industry is on the verge of a new and exciting innovation cycle. The modularization of the staking tech stack, led by advances in middleware solutions such as Obol Network (Distributed Validator Technology), Flashbots (MEV Boost), Liquid Collective (liquid staking), and EigenLayer will create a new playing field for existing operators, product builders and solo stakers.
This panel seeks to discuss these important developments and the new benefits and risks they bring to Ethereum.
Collin Myers, Sreeram Kannan, Viktor Bunin | Coinbase Cloud, Stephane Gosselin
Promoting Small and Independent Stakers: Q&A with the Ethereum Staking Protocols
The Node Operator Association presents a roundtable discussion on promoting small and independent professional stakers. Topics include operator qualifications, application processes, costs, risks, each platform's unique advantages, and their vision for the future of Ethereum staking.
Panelists: Darren Langley (Rocket Pool) Vasiliy Shapovalov (Lido) Oisin Kyne (Obol) Jordan Sutcliffe (Stakewise) Ariel Zimroni (SSV Network)
Ken Smith, Oisín Kyne, Darren Langley, Mike Leach, Ariel Zimroni, Jordan Sutcliffe, Vasiliy Shapovalov
Run Your Own Beaconcha.in
In this workshop we will show participants how to setup and run the [beaconcha.in-explorer](https://beaconcha.in) for existing networks (mainnet, prater, sepolia) as well as for custom networks. Also we will explain how to analyze the network using the explorer and how to monitor validators. By doing this workshop we hope to learn about problems people are running into while trying to run the explorer on their own and improve the usabilty of the explorer in general.
Patrick Pfeiffer, Stefan Starflinger
Spin it up - spin up your own Ethereum validator on testnet
This workshop aims to be an essential introduction to Ethereum PoS consensus by inspecting its underlying infrastructure.
We will first demystify concepts such as Execution + Consensus layer, PoS validation, Keys and Signatures, and Slashing.
You will learn by watching when we demo how to spin up a validator using the Lighthouse validator client.
You will learn by doing when we give you some time to spin up a validator yourself and experiment with the setup.
Jennifer Parak, Gabriella Sofia
The Future of Liquid Staking
Liquid staking is now a major factor is the staking economy and staking protocol design. I'm going to lay out how I think it's going to interact with future DeFi, protocol development, MEV, interchain communication, L2s and modular blockchains. How liquid staking protocols will have to change with the blockchain world, and how to make them to shape themselves better.
Under 2 Min - Become an Ethereum Staker and Set Up Node
We need more mainstream users to partake in Etheruem PoS activity, A brief talk showcasing stake tooling for Ethereum deposit contract that allows a normal user to safely stake 32 ETH and have his/her Ethereum Validator from 0, this includes generating credentials and processing deposit, another 60 seconds will allow them to have a node up and running using DVT techstack.
Validating Made Light and Simple
The network has seen an increase in staked Eth led by staking pools, liquid staking protocols, CEX and solo stakers. The complexity of running multiple clients (Execution, Consensus, Beacon and possibly MEV) means that validating is increasingly considered an organised activity for teams of specialists. Nimbus is pushing for simplification to ensure it remains accessible to individuals and institutions alike. In this talk, Nimbus presents its vision for the future of Ethereum client experience
Why and How to Run a Node! (No ETH Required)
The foundation of Ethereum is a resilient and decentralized network of nodes. You’ll learn how nodes defend the network, the easiest ways to run a node, about the upcoming upgrades to Ethereum which make it easier to run a node, and more.