xAI

Overview

xAI is an American AI company founded by Elon Musk in March 2023 after his departure from OpenAI's board. Musk has positioned xAI as building "maximally truth-seeking AI" and has been outspoken in his criticism of OpenAI's direction.

Grok

xAI's flagship product is Grok, a chatbot integrated into the X (formerly Twitter) social platform. Grok is unique among major chatbots for its real-time access to X data and its more permissive content policies.

• Grok 1 (Nov 2023) — first release, later open-weighted
• Grok 2 (Aug 2024) — multimodal upgrade
• Grok 3 (Feb 2025) — trained on the Colossus supercluster
• Grok 4 (2025) — current flagship reasoning model

Colossus

In September 2024, xAI brought online Colossus, a 100,000-GPU H100 supercluster in Memphis, Tennessee — built in 122 days and described as the largest contiguous AI training cluster in the world. xAI has announced plans to expand it to 1 million GPUs.

Twitter/X relationship

xAI acquired X (the social network) from Elon Musk in March 2025 in an all-stock deal valuing X at US$33 billion and xAI at US$80 billion, creating xAI Holdings.