Imbue
Agents that use computers — and the sandboxes to train them.
Imbue (formerly Generally Intelligent) builds agents that reason and operate computers autonomously, and open-sourced Sextant, a sandbox environment purpose-built for computer-use agent training and evaluation.
In the news
First 'Harness Engineering' survey lands on arXiv
'Harness Engineering: Anatomy, Architecture, and Evolution of Coding Agents' surveys the field — loops, tool interfaces, context management, memory and recovery — giving the emerging discipline its first comprehensive academic map.
HarnessTax: harness choice swings agent cost more than model choice
Arena.ai's HarnessTax study tests 21 model–harness combinations across Claude Code, Codex CLI and Pi, finding harness choice can significantly change cost even at similar task success rates. Weeks earlier, SWE-bench Pro analysis showed swapping harnesses moved pass@1 more than model upgrades (23%→52% on GLM-5.2) — and that harness rankings barely transfer across models.
Related startups
Cognition
Devin, the AI software engineer, and the Windsurf IDE.
Cognition builds Devin, an autonomous AI software engineer that plans and executes engineering tasks end-to-end, and acquired the Windsurf agentic IDE in 2025. One of the defining startups of the coding-agent wave.
Cursor (Anysphere)
The AI-native code editor where agent mode lives.
Cursor rebuilt the IDE around models: tab completion, in-editor chat and agent mode that plans multi-file edits and runs commands. Its rise set the pace for the entire coding-agent market.
Factory
Droids: AI workers for software teams.
Factory's 'droids' take engineering tickets from issue to pull request, with sandboxed environments and enterprise controls — agents as members of the dev workflow.