About

Isaacus is an AI research company building legal superintelligence.

We currently offer a suite of state-of-the-art information retrieval, classification, extraction, and enrichment models that help supercharge legal AI applications.

As proud supporters of open research, we maintain popular open-source datasets and libraries such as the Massive Legal Embedding Benchmark (MLEB), Legal RAG Bench, Open Australian Legal Corpus, and semchunk.

We’re based in Melbourne, Australia, and Riyadh, Saudi Arabia, but operate internationally, serving law firms, enterprises, and governments in the US, UK, Canada, Europe, India, and elsewhere.

If you’d like to partner with us on the development of custom AI models, secure a sovereign deployment of our existing models, or invest in Isaacus, reach out via our contact page. Members of the press may also consult our media kit to access our core brand assets.

Team

The Isaacus team, led by Umar Butler, an internationally recognized legal AI researcher, combines advanced knowledge of AI and statistics with deep expertise in law and regulation, spanning 35 years of industry experience across three countries.

  • Umar Butler

    Umar Butler

    Founder & CEO

    Umar Butler is the founder and CEO of Isaacus, an internationally recognized legal AI researcher.

    His most well-known works include the Open Australian Legal Corpus, Open Australian Legal LLM, Massive Legal Embedding Benchmark (MLEB), and semchunk.

    Previously, Umar was the Assistant Director of Data Science at the Attorney-General’s Department, where he was responsible for overseeing all the Department’s national-level AI projects.

    His formal qualifications are in law, holding a Bachelor of Laws (Honours) and Bachelor of Arts from La Trobe University.

  • Abdur-Rahman Butler

    Abdur-Rahman Butler

    Cofounder & COO

    Abdur-Rahman Butler is a cofounder and the COO of Isaacus, a technical marketer by trade and economist by education.

    He is a creator of the Massive Legal Embedding Benchmark (MLEB), Legal RAG Bench, and Oases of Wisdom, a popular YouTube channel covering medieval philosophy.

    Abdur-Rahman completed a Master of Economics at Monash University in 2025, receiving the Dean’s Unit Prize for Applied Microeconomics upon graduating.

  • Tabs Fakier

    Tabs Fakier

    Founding DevRel Engineer

    Tabs Fakier is a DevRel engineer at Isaacus, building legal RAG systems and developer tooling.

    Tabs works on documentation, sample applications, and the integrations that help legal tech teams ship with Isaacus models and APIs.

  • Yasin

    Yasin

    ML Engineer

    Yasin wrangles data and builds the infrastructure and products that power foundational legal AI.