[ANN] Copilot 4.6

[ivanperez-keera]

Hi everyone!!

We are really excited to announce Copilot 4.6.

This major release improves the Bluespec backend, producing more suitable Verilog code. Prior implementations required modifying the resulting Verilog to help connect it to external systems (e.g., sensors, actuators), while the new Bluespec backend produces code that can be used without modification.

The new implementation is compatible with versions of GHC from 8.6 to 9.12.

This release has been made possible thanks to Sukhman Kahlon (NASA), who carried out a thorough evaluation of our FPGA backend, and to Ryan Scott (Galois), who implemented the updated solution. This work has also greatly benefited from discussions with the Bluespec team on the code generated by Copilot and possible improvements. We are grateful to all of them for their contributions, and for making Copilot better every day.

For details on this release, see: https://github.com/Copilot-Language/copilot/releases/tag/v4.6.

As always, we're releasing exactly 2 months since the last release. Our next release is scheduled for Jan 7th, 2026.

We want to remind the community that Copilot is now accepting code contributions from external participants again. Please see the discussions and the issues to learn how to participate.

Current emphasis is on using Copilot for full data processing applications (e.g, system control, arduinos, rovers, drones), improving usability, performance, and stability, increasing test coverage, removing unnecessary dependencies, hiding internal definitions, and formatting the code to meet our coding standards. Users are encouraged to participate by opening issues, asking questions, extending the implementation, and sending bug fixes.

Happy Haskelling!

Full Changelog: v4.5.1...v4.6