Informal Systems Announces Malachite Acquisition by Circle to Power New Arc Blockchain Network

High-performance BFT consensus engine powers Circle's new stablecoin-focused Layer-1 blockchain launching in testnet later this year.

TORONTO, Aug. 18, 2025 /PRNewswire/ -- Informal Systems, a leader in blockchain infrastructure and protocol design, announced on August 12 that its high-performance consensus engine, Malachite, has been acquired by Circle Internet Group, Inc. (NYSE: CRCL) (Circle), a global financial technology firm, to support the launch of Arc¹, a new open Layer-1 blockchain network purpose-built for stablecoin finance. Arc is expected to debut in testnet later this year.

Founded by experts in formal methods and distributed systems, Informal Systems builds transformative technologies to foster trust in software and money. Malachite is the product of years of pioneering work in consensus and verifiability—a Byzantine Fault Tolerant (BFT) consensus engine implementing the Tendermint algorithm in a modular design focused on correctness and efficiency. Originally developed to meet real-world demands for a flexible, reusable foundation for decentralized systems.

Circle's integration of Malachite will help bring greater performance, reliability, and security to stablecoin-based payments, reinforcing Malachite's mission to deliver trustworthy, low-cost, and borderless financial infrastructure. The Malachite repository will remain open source under the Apache 2.0 license, ensuring continued industry access and innovation.

"This acquisition is a strong validation of Malachite and of our incubation model," said Ethan Buchman, CEO at Informal Systems. "Circle's adoption of Malachite provides a high-impact use case, a robust financial foundation for future development, and ensures our technology contributes to meaningful, mission-aligned outcomes."

The acquisition aligns with Informal's broader strategy of spinning out incubated projects to accelerate their growth. Alongside Malachite, Informal is advancing initiatives such as Cycles, Hydro, and Quint, a leading tool for complex distributed systems that supported Malachite's development. Several Informal team members will join Circle to drive Arc's development, while Informal continues to support other Malachite use cases and collaborate with industry partners on next-generation blockchain applications.

"We're proud of the exceptional talent and technical depth nurtured at Informal," said Arianne Flemming, COO. "This transition reflects our commitment to ensuring that the technologies we create serve the most transformative purposes possible."

Informal will continue working with leading teams on protocol design and cross-chain infrastructure, offering engineering and security expertise to organizations building with Malachite and beyond. For collaboration inquiries, contact hello@informal.systems.

¹ Arc is offered by Circle Technology Services, LLC ("CTS"). CTS is a software provider and does not provide regulated financial or advisory services. You are solely responsible for services you provide to users, including obtaining any necessary licenses or approvals and otherwise complying with applicable laws.