Earendil

Earendil develops AI software for developers and people working through everyday communication tools. Pi is an open-source coding agent and harness that developers can extend or build into their own products. Lefos, built on Pi, operates through email and Telegram: users can bring colleagues into conversations, translate messages, edit drafts, analyze documents and schedule recurring tasks. Optional Google Workspace access lets it create documents, retrieve information and schedule calendar invitations.

Armin Ronacher and Colin Daymond Hanna founded Earendil as a public benefit corporation in 2025. The company acquired Pi in 2026, bringing its creator, Mario Zechner, onto the team as a major stakeholder. Zechner leads Pi’s technical direction alongside the founders. Pi also powers OpenClaw, while Earendil uses it both as infrastructure for its products and as a coding tool to build them.

Earendil’s business strategy combines an MIT-licensed core with planned commercial additions under Fair Source and proprietary licenses, including cloud infrastructure. Pi’s use extends into enterprise engineering: in 2026, Shopify used its own Pi-based autoresearch extension to improve more than 40 engineering metrics through repeated experiments.