#1755 introduces a new implementation of the compatibility layer that pushes it into Rust and wraps quil-rs directly. This addresses both API consistency and performance issues of the existing compatibility layer. See the description of #1755 for details of the proposal.

This milestone tracks all the work items that are needed for this new backend to reach feature parity with the existing backend. When this milestone is complete, users should be able to use the new backend without compromising anything from the existing backend.

Version 3.0 of PyQuil is on the way! New features: 1) Cleaner, more reliable access to the QCS API via the qcs-api-client, which includes a change to the configuration file format; 2) Smaller, simpler codebase focused on supporting the Quil language and experimentation rather than serving as the defacto RIgetti SDK; 3) mproved user control and configuration; 4) Improved error messaging and handling; 5) Improved package management and distribution.

We intend to make the transition from v2.x to v3.x as easy as possible for developers, with minimal breaking changes and thorough documentation about any that we choose to make. We'll be publishing release candidates along the way for which feedback is very welcome. We plan to release v3.0.0 in the first half of 2021.