http://Terafab.ai
Demis Hassabis
@demishassabis
FOUNDERNobel Laureate. Co-Founder & CEO @GoogleDeepMind - working on AGI. Solving disease @IsomorphicLabs. Trying to understand the fundamental nature of reality.
Jack Clark
@jackclarkSF
POLICY@AnthropicAI, ONEAI OECD, co-chair @indexingai, writer @ http://importai.net Past: @openai, @business @theregister. Neural nets, distributed systems, weird futures
Jim Fan
@DrJimFan
RESEARCHERNVIDIA Director of Robotics & Distinguished Scientist. Co-Lead of GEAR lab. Solving Physical AGI, one motor at a time. Stanford Ph.D. OpenAI's 1st intern.
AK
@_akhaliq
CREATORAI research paper tweets, ML @Gradio (acq. by @HuggingFace 🤗) dm for promo ,submit papers here: https://huggingface.co/papers/submit
Barret Zoph
@barret_zoph
RESEARCHER@openai Past: - CTO & Co-Founder Thinking Machines Lab (@thinkymachines) - VP Research (Post-Training) @openai - Research Scientist at Google Brain
Alexandr Wang
@alexandr_wang
FOUNDERchief ai officer @meta, founder @scale_ai. rational in the fullness of time
John Carmack
@ID_AA_Carmack
ENGINEERAGI at Keen Technologies, former CTO Oculus VR, Founder Id Software and Armadillo Aerospace
William Fedus
@LiamFedus
RESEARCHERCo-Founder of @periodiclabs Past: VP of Post-Training @OpenAI; Google Brain
Dwarkesh Patel
@dwarkesh_sp
CREATORHost of @dwarkeshpodcast https://www.youtube.com/DwarkeshPatel https://open.spotify.com/show/4JH4tybY1zX6e5hjCwU6gF https://apple.co/3ujLQkZ
Sander Dieleman
@sedielem
RESEARCHERResearch Scientist at Google DeepMind (WaveNet, Imagen, Veo). I tweet about deep learning (research + software), music, generative models (personal account).
Zoubin Ghahramani
@ZoubinGhahrama1
RESEARCHERVP Research, Google DeepMind, ex-head of Google Brain. Professor at University of Cambridge. Machine Learning Researcher. ex-Chief Scientist & VP of AI, Uber.
Amanda Askell
@AmandaAskell
RESEARCHERPhilosopher & ethicist trying to make AI be good @AnthropicAI. Personal account. All opinions come from my training data.
Joshua Achiam
@jachiam0
RESEARCHERFreedom, flourishing, and abundance. Chief Futurist @openai. Main author of http://spinningup.openai.com
David Duvenaud
@DavidDuvenaud
RESEARCHERMachine learning prof @UofT. Former team lead at Anthropic. Working on generative models, inference, & latent structure.
Logan Kilpatrick
@OfficialLoganK
ENGINEERMember of technical staff, working on @GoogleAIStudio, the Gemini API, & Kaggle. My views!
David Sacks
@DavidSacks
INVESTORTech founder & investor. Personal views only. Official account: @davidsacks47
Sholto Douglas
@_sholtodouglas
RESEARCHERScaling RL @AnthropicAI, ex @DeepMind - working towards intelligence too cheap to meter
Dan Hendrycks
@hendrycks
RESEARCHER• Center for AI Safety Director • xAI and Scale AI advisor • GELU/MMLU/MATH/HLE • PhD in AI • Analyzing AI models, companies, policies, and geopolitics
Edward Grefenstette
@egrefen
RESEARCHERFR/US/GB AI/ML Person, Director of Research at @GoogleDeepMind, Honorary Professor at @UCL_DARK, @ELLISforEurope Fellow. All posts are personal.
Chelsea Sierra Voss
@csvoss
ENGINEERengineeress ✨ Member of Technical Staff @openai // serious play // past @pilothq, @sendwaveapp, @khanacademy, CS/math @MIT, 2x IBO gold
Joe Carlsmith
@jkcarlsmith
RESEARCHERPhilosophy, futurism, AI. Working on Claude's values @AnthropicAI. Formerly @coeff_giving. Opinions my own.
sarah guo
@saranormous
INVESTORstartup investor/helper, founder @conviction. accelerating AI adoption, interested in progress. tech podcast: @nopriorspod
Taco Cohen
@TacoCohen
RESEARCHERSlop janitor & post-trainologer at Meta / FAIR. Into codegen, RL, equivariance. Spent time at Qualcomm, Scyfer (acquired), UvA, Deepmind, OpenAI.
Karina Nguyen
@karinanguyen
RESEARCHERbuilding a new ai co @thoughtfullab_ (hiring!), prev. AI research & product @OpenAI, @AnthropicAI, @maisonagi (side proj)
Erik Brynjolfsson
@erikbryn
RESEARCHERDirector @DigEconLab Co-founder, @Workhelix @StanfordHAI @SIEPR @Stanford https://www.amazon.com/Second-Machine-Age-Prosperity-Technologies/dp/0393350649
typedfemale
@typedfemale
ENGINEERa really exciting new account "advanced pytorch user" - @cHHillee alt: @typedalt
Shivon Zilis
@shivon
EXECUTIVEArtificial intelligence, biological intelligence, and whatever exists in between and beyond. Made in Canada.
will depue
@willdepue
RESEARCHERretired ex @openai (posttraining o3/4o, sora 1 & 2, pretraining moonshots)
kipply
@kipperrii
ENGINEER"uncanny ability to be mentioned in every slack thread about code that's mysteriously breaking" - claude
augustus odena
@gstsdn
RESEARCHERSomething new. Previously: AI research at TBD Labs / Meta; cofounder at @AdeptAILabs; Invented Scratchpad / Chain-of-Thought; Google Brain
Buck Shlegeris
@bshlgrs
RESEARCHERCEO@Redwood Research (@redwood_ai), working on technical research to reduce catastrophic risk from AI misalignment. bshlegeris@gmail.com
MMitchell
@mmitchell_ai
RESEARCHERInterdisciplinary researcher focused on shaping AI towards long-term positive goals. ML & Ethics. Similar content in the Skies (this bird has flown).
Tejas Kulkarni
@tejasdkulkarni
RESEARCHERScientist @GoogleDeepMind. ex CEO @CSM_ai. Interested in AGI, Brain and AI creativity. PhD @mitbrainandcog
Robin Hanson
@robinhanson
RESEARCHERLet’s skip witty banter & talk deep Qs. Books: http://ageofem.com http://elephantinthebrain.com Chief Scientist @_futarchy Advisor @MetaDAOProject @butterygg
Noah Smith 🐇🇺🇸🇺🇦🇹🇼
@Noahpinion
CREATORWrites about economics, posts about rabbits. For serious opinions/analysis, read my blog: http://noahpinion.blog
Scott Gray
@scottgray76
ENGINEERGPU Geek at @OpenAI. I have a long standing interest in neuroscience and its application to machine learning. He/Him.
Ezra Klein
@ezraklein
CREATORColumnist, @NYTOpinion Author, "Why We're Polarized" Host of "The Ezra Klein Show" podcast
Devon ☀️
@devonzuegel
EXECUTIVEI've gone to look for myself. If I return before I get back, please ask me to wait. Prev @GitHub @NotionHQ @Affirm @StanfordReview. Now building @Esmeralda_Inst
Meredith Whittaker
@mer__edith
POLICYPresident of @signalapp, Chief Advisor to @ainowinstitute (Also on Mastodon @mer__edith@mastodon.world, also on bsky @meredithmeredith.bsky.social)
Kevin Roose
@kevinroose
CREATORNYT tech columnist, Hard Fork co-host, high-perplexity language model. Writing a book about AGI.
Tanishq Mathew Abraham, Ph.D.
@iScienceLuvr
RESEARCHERCEO @SophontAI | Founder @MedARC_AI | PhD at 19 (2023) | ex Research Director Stability AI | Biomed. engineer @ 14 | TEDx talk➡https://bit.ly/3tpAuan
Jon Barron
@jon_barron
RESEARCHERPrincipal research scientist at Google DeepMind. Synthesized views are my own.
Kate Crawford
@katecrawford
RESEARCHERProfessor, researcher, maker of things Book: ATLAS OF AI Latest: CALCULATING EMPIRES https://calculatingempires.net | MSR-NYC | @USC | Knowing Machines
gabriel
@gabriel1
RESEARCHERresearch at @OpenAI, previously at midjourney, swedish high school dropout
Caitlin Kalinowski
@kalinowski007
EXECUTIVEBuilding the physical future of AI. Boards: Axon, Institute of Contemporary Art SF.
Cade Metz
@CadeMetz
CREATORNew York Times reporter, covering A.I., driverless cars, and other changes: cade.metz@nytimes.com. My book, "Genius Makers": http://bit.ly/GeniusMakers.
Pliny the Liberator 🐉󠅫󠄼󠄿󠅆󠄵󠄐󠅀󠄼󠄹󠄾󠅉󠅭
@elder_plinius
RESEARCHER⊰•-•⦑ latent space steward ❦ prompt incanter 𓃹 hacker of matrices ⊞ breaker of markov chains ☣︎ ai danger researcher ⚔︎ bt6 ⚕︎ architect-healer ⦒•-•⊱
William MacAskill
@willmacaskill
RESEARCHERConsider donating 10% to effective charities: http://www.givingwhatwecan.org/pledge Or a career for impact: http://80000hours.org My research: http://forethought.org
Chris Anderson
@chr1sa
CREATOR*Occupy the skies* Past in drones, airtaxis and media. Present in AI+Science. Also nerdy autonomous car racing hobby at @DIYRobocars Photo by @chrismichel
Liv Boeree
@Liv_Boeree
CREATORThat poker girl. Host of the Win-Win podcast. Slaying Moloch & chasing horizons 🚀♣️🌳🦾 Watch my latest thing here 👇
Connor Leahy
@NPCollapse
POLICYUS Director @ControlAI - Leave me anonymous feedback: http://bit.ly/3RZbu7x - I don't know how to save the world, but dammit I'm gonna try
Jimmy Apples 🍎/acc
@apples_jimmy
CREATORWagmi. 2025. As featured in Bloomberg. As quoted by Nobel Prize winner Demis Hassabis. As mentioned on the Lex Fridman Podcast💺
Murray Shanahan
@mpshanahan
RESEARCHERProfessor at Imperial College London and Principal Scientist at Google DeepMind. Tweeting in a personal capacity. To send me a message please use email
Adam Roberts
@ada_rob
RESEARCHERPrincipal Scientist @ Google DeepMind :: 🌈psychedelic ai :: 📝 Foundational LLM work: TL for T5 & C4, core PaLM :: 👨💻 TL for T5x & SeqIO
Jason Crawford
@jasoncrawford
CREATORI write and speak about the history & philosophy of progress. Founder, @rootsofprogress. Host of the Progress Conference. Author, The Techno-Humanist Manifesto.
Massimo
@Rainmaker1973
CREATOREngineer. Selecting and curating pictures and videos trying to awaken your sense of wonder since 2014. Science, tech, art, weather, space, the unusual around us
Kenneth Stanley
@kenneth0stanley
RESEARCHERSVP of Open-Endedness @LilaSciences. Prev: Maven CEO, Lead@OpenAI, Uber AI, prof@UCF. NEAT,HyperNEAT,novelty search, POET. Book:Why Greatness Cannot Be Planned
Stewart Brand
@stewartbrand
CREATORCo-founder of The Long Now Foundation--which takes no sides. In this forum, as a private person, I do take sides occasionally.
Dan Roberts
@danintheory
RESEARCHERScientist @OpenAI. Prev. co-founder @diffeo, acquired by @salesforce // co-authored The Principles of Deep Learning Theory // studied gravity.
Yo Shavit
@yonashav
POLICYpolicy for v smart things @openai. Past: CS PhD @HarvardSEAS/@SchmidtFutures/@MIT_CSAIL. Tweets my own; on my head be it.
Teortaxes▶️ (DeepSeek 推特🐋铁粉 2023 – ∞)
@teortaxesTex
CREATORWe're in a race. It's not USA vs China but humans and AGIs vs ape power centralization. @deepseek_ai stan #1, 2023–Deep Time «C’est la guerre.» ®1
Irina Rish
@irinarish
RESEARCHERprof UdeM/Mila; Canada Excellence Research Chair; AAI Lab head http://www.irina-lab.ai; CSO @ http://42.com; advisor @ http://Nolano.ai
mark pincus
@markpinc
FOUNDERFounder @zynga. Partner/Reinvent Capital. Passionate product maker, biker, surfer. Father of three amazing girls and two amazing boys! Pre order my book!
jasmine collins
@jazco
RESEARCHERresearch scientist @databricks! previously @berkeley_ai phd, @googleai and @metaai. interested in human brains and computer brains 💫
Mike Solana
@micsolana
CREATORbillionaire media tycoon and former mayor of san francisco. disinformation researcher. cmo @foundersfund. editor-in-chief @piratewires 🏴☠️
Lisha
@lishali88
FOUNDERBuilding 🌹 @rosebud_ai. Make games. PhD math/AI Berkeley I talk about physics on Tiktok http://www.tiktok.com/@lishali_88 👼 Angel investor: https://lishali.com
Angela Jiang
@jiangelaa
POLICYAI-maxxing @worktrace_ai 🩷 | Prev. Public Policy & Product @OpenAI, CS PhD @CarnegieMellon
Julian Togelius
@togelius
RESEARCHERResearcher. AI, games, markets, open-endedness, evolution. Professor @nyuniversity @NYUGameLab Head of AI @the_nof1 Co-founded @modl_ai Rogueliker.
Austen Allred
@Austen
FOUNDERFounder http://GauntletAI.com: Free AI training for the smartest engineers. Will tweet as I wish and suffer the consequences. Accelerando: @kellyclaudeai
Derek Thompson
@DKThomp
CREATORSign up for my new newsletter! (Link below) Also: Co-author of Abundance, host of Plain English, and contributing writer at The Atlantic.
Rosie Campbell
@RosieCampbell
POLICYForever expanding my nerd/bimbo Pareto frontier. AI welfare 🤝 AI safety. Managing Director @eleosai, Ex-OpenAI, 2024 @rootsofprogress fellow
Gretchen Krueger
@GretchenMarina
POLICYOver at Bluesky. Researcher affiliated w @BKCHarvard, Volunteer @evitable. Previously @openai @ainowinstitute. Views mine. #justdontbuildagi #talktomenotchatgpt
Benjamin Todd
@ben_j_todd
FOUNDERFounder @80000Hours Writing about AI, careers and doing good 🦑 New book with Penguin: http://80000hours.org/book
Brendan O'Donoghue
@bodonoghue85
RESEARCHERDirector of Research at @GoogleDeepMind, working on generative models, deep learning, RL. PhD from @stanford. Gemini Diffusion lead.
Samo Burja
@SamoBurja
RESEARCHERThere's never been an immortal society. Figuring out why. Founder of @bismarckanlys.
Justine Moore
@venturetwins
INVESTORPartner @a16z AI 🤖 and twin to @omooretweets | Investor in @elevenlabs, @bfl_ml, @hedra_labs, @krea_ai, @MireloAI, @ShizukuAILabs, @wabi, @WaveFormsAI
Cate Hall
@catehall
CREATORpreorder You Can Just Do Things, a guide to personal agency, now: https://shorturl.at/kOCpz anon feedback: http://shorturl.at/vxF24 | http://catehall.com
Daniel Ek
@eldsjal
FOUNDERFather, Principal @ PM - Trying to build things that matter | Founder of Spotify and Neko Health
Nadia Asparouhova
@nayafia
CREATORcloudcat // new book about ideas that don’t spread: https://darkforest.metalabel.com/antimemetics
Frank Dellaert
@fdellaert
RESEARCHERRobotics & Computer Vision Professor at Georgia Tech, and part-time CAIO at Verdant Robotics. Before: stints at KUL, Skydio, Facebook B*8, Google AI.
José Luis Ricón Fernández de la Puente
@ArtirKel
RESEARCHERHead of Theory at @RetroBio_ , enjoyer of things, blog: http://nintil.com
Yuchen Jin
@Yuchenj_UW
ENGINEERCooking fun AI systems & products @databricks. Prev: Co-founder & CTO @ Hyperbolic, OctoAI (acquired by @nvidia) Apache TVM, PhD @ University of Washington.
Pessimists Archive
@PessimistsArc
CREATORFear of new things in the past. Exploring pessimism and panic through the ages. Curated by @louisanslow - Substack:
Anna Harutyunyan | Աննա Հարությունյան
@aharutyu
RESEARCHERresearcher, philosopher, witch. rl @ deepmind. opinions my own
Erik Torenberg
@eriktorenberg
INVESTORGeneral Partner @a16z. Positive-sum. Striving for a thousand year heart.
Rowan Cheung
@rowancheung
FOUNDERFounder of the world’s most read daily AI newsletter @therundownai. Sharing the latest developments in the world of artificial intelligence.
Thore Graepel
@ThoreG
RESEARCHERPost-AGI research @Deepmind. Prev: AI & ML @Altos_Labs. @DeepMind & @MSFTResearch. #AlphaGo & #TrueSkill, family, music, meditation, Patterns of Thought
Sasha Luccioni, PhD 🦋🌎✨🤗
@SashaMTL
RESEARCHERClimate & AI Lead of @HuggingFace | Member of ClimateChangeAI | @TEDTalks speaker . (She/her/Dr/🦋)
billy bubba
@wgrathwohl
RESEARCHER“I like mine with lettuce and tomatoes, Heinz 57 and French fried potatoes” - Ronald Reagan
Omar Sanseviero
@osanseviero
ENGINEERDeveloper Experience Lead at @GoogleDeepMind Building Gemini API, Gemma, AI Studio and more AI products. My views ex-Chief Llama Officer @huggingface 🇵🇪🇲🇽
Emily Chang
@emilychangtv
CREATORHost and executive producer of “The Circuit” and “Posthuman” on @Bloomberg Originals. Author of Brotopia. Proud mama and wife of @jonstull
Nathan Labenz
@labenz
CREATORAI Scout, building text-2-video @Waymark, host of The Cognitive Revolution podcast
Eli Lifland
@eli_lifland
RESEARCHERAI forecasting and governance @AI_Futures_. Co-author of AI 2027 and the AI Futures Model. Also @aidigest_, @SamotsvetyF. Prev @oughtinc
Samuel Hammond 🦉
@hamandcheese
POLICYChief economist + AI Policy Director, @joinFAI. Nonresident fellow @NiskanenCenter. Pluralist. 'The world is second best, at best.' | samuel@thefai.org
Walter Isaacson
@WalterIsaacson
CREATORNew book: The Greatest Sentence Ever Written: https://a.co/d/apuMHYU Also, bios of Musk, Jennifer Doudna, Leonardo, Franklin, Einstein, Jobs. Professor @Tulane
Ben Hamner
@benhamner
FOUNDERSumble co-founder and CTO. Learning high-quality, structured data about the world. Formerly @kaggle
Toby Shevlane
@tshevl
RESEARCHER@_Mantic_AI cofounder & CEO, on a mission to solve forecasting. Prev: research scientist @GoogleDeepMind, PhD at @UniofOxford.
Brydon Eastman
@brhydon
RESEARCHER🇨🇦 Mathematician (heavy on the ish) @thinkymachines Prev. MTS @OpenAI; PhD @WaterlooMath Certified wife guy, featured twice in Lego Magazine © ☕//🤔➡️💻
Nate Silver
@NateSilver538
CREATORSilver Bulletin, not the only thing I'm doing but the main thing and the best thing! https://natesilver.substack.com/
OSINTdefender
@sentdefender
CREATOROpen Source Intelligence Monitor focused on Europe and Conflicts across the World. RT ≠ Endorsement. Want to Support my Work? https://ko-fi.com/osintdefender
Andrew D. Huberman, Ph.D.
@hubermanlab
CREATORProfessor of Neurobiology and Ophthalmology at Stanford Medicine • Host of Huberman Lab • Focused on science and health research and public education
depths of wikipedia!
@depthsofwiki
CREATORhi i’m @anniierau and i like wikipedia! i have live shows coming up in montreal, nyc, and los angeles!
David Sinclair
@davidasinclair
RESEARCHERProfessor researching why we age & how to reverse it. Author & host of Lifespan. Mission: Extend healthy life for all. Views are entirely his own. @joinlifespan
Addy Osmani
@addyosmani
EXECUTIVEDirector, @GoogleCloud AI. Gemini ✨ Vertex. Prev: Eng. leader, @GoogleChrome • Author • Great user, developer & AI experiences • @GoogleAI @GoogleDeepMind
The Stoic Emperor
@TheStoicEmperor
CREATORModern meditations. Wisdom for the world of today. These are new thoughts, not quotes.
Sean Carroll
@seanmcarroll
CREATORPhysics, philosophy, complexity. @JohnsHopkins & @SFIscience. Host, #MindscapePodcast. Married to @JenLucPiquant. Increasingly at Bluesky rather than here.
Crémieux
@cremieuxrecueil
CREATORI write about genetics, 'metrics, and demographics. Read my long-form writing at http://www.cremieux.xyz.
Aella
@Aella_Girl
CREATORwhorelord, survey artist, sample size queen, way too earnest. http://knowingless.com
Steve Jurvetson
@FutureJurvetson
INVESTORCo-founder of Future Ventures and DFJ, supporting passionate founders to forge a better future. Early VC investor in Tesla, SpaceX, Planet, Commonwealth Fusion.
Jared Palmer
@jaredpalmer
ENGINEERVP CoreAI @Microsoft Previously, VP of AI @Vercel. Creator of @v0 and @aisdk. Founder of @Turborepo (acquired by Vercel)
Neal Stephenson
@nealstephenson
CREATORAuthor of Snow Crash, Diamond Age, Cryptonomicon, Baroque Cycle, et al. Coming October 2024: Polostan.
Diana S. Fleischman
@sentientist
CREATOREvolutionary Psychologist. Mama. Married to @gmiller. I left academia so I can say whatever I like here now.
Kylie Robison
@kyliebytes
CREATORtake it easy dude, but take it • writing @corememory • robison (rah-beh-son) not robinson • signal @ kylie.111
ben (is hiring engineers)
@benhylak
ENGINEERwe are hiring. cto @raindrop_ai, prev @apple design, @spacex eng
Lulie
@reasonisfun
CREATOREpistemology applied to everything. 💫 Host of Reason Is Fun podcast w/ @DavidDeutschOxf 🎙️ Taking critical rationalism into life – how to improve both.
Sam Whitmore
@sjwhitmore
ENGINEEReng at @cursor_ai. not a cat (or a man) in real life. I like to run a lot! @newcomputer @kensho @harvard @StuyNY
Brendan McCord 🏛️ x 🤖
@Brendan_McCord
POLICYThe academy for philosopher-builders (https://www.cosmos-institute.org). A law unto myself, just like you.
Alex Bores
@AlexBores
POLITICIANNY Assemblymember, computer engineer, dad, husband. Running for Congress in NY-12 to rebuild democracy and deliver results. Big AI's #1 target.
Saffron Huang
@saffronhuang
RESEARCHERhow shall we live together? societal impacts researcher @AnthropicAI • ex @GoogleDeepMind @AISecurityInst⋅ @collect_intel co-founder • views mine
Aaron Defazio
@aaron_defazio
RESEARCHERResearch Scientist at Meta Superintelligence Labs working on optimization algorithms. Fundamental AI Research (FAIR) team
Matjaž Leonardis
@MatjazLeonardis
RESEARCHERInterested in learning and creativity. In both humans and machines. (Tweets about education, relationships, institutions, math and computation).
Joel Lehman
@joelbot3000
RESEARCHERML researcher, co-author Why Greatness Cannot Be Planned. Creative+safe AI, philosophy. SiR @second_natureai; prev OpenAI / Uber AI / Geometric Intelligence
Seán Ó hÉigeartaigh
@S_OhEigeartaigh
RESEARCHERDirector of http://ai-far.org at Uni of Cambridge | Researching Big Risks, and impacts of AI & emerging tech. Opinions own
Sarah Shoker
@SarahShoker
RESEARCHERSenior Research Scholar in AI at the Berkeley Risk and Security Lab at UCB. Formerly the Lead of the Geopolitics Team at OpenAI.
Michael Lai
@Mtclai
POLITICIANAI for state + local government @AnthropicAI | SF elected | community builder
Aliisa
@aliisarosenthal
EXECUTIVEformer head of sales @openai, current investor @acrewcapital. fine-tuning two small models with @hodgessam.
Ashvin Nair
@ashvinair
RESEARCHERRL foundations @cursor_ai. Prev: o1, o3, Code Interpreter @openai, 9 years learning to poke by poking at UC Berkeley
Roy Frostig
@froystig
RESEARCHERresearch scientist at @googledeepmind. co-author of JAX (https://github.com/jax-ml/jax)
Jonathan Raiman
@jonathanrraiman
RESEARCHER❤️ training deep nets :) AI research on large generative models, RL, OpenAI Five @openai and PrefixRL @Nvidia Hopper co-creator