Lyra: A Modern SystemVerilog Simulation Toolchain

Lyra is a SystemVerilog compiler and simulator built the way a modern language toolchain is built: around independently compilable units with explicit dependencies, where incremental and parallel compilation are constraints on the design rather than optimizations added to it later.

The goal is a fast edit-run loop rather than peak simulation speed. Those two pull in different directions, and Lyra picks the loop. A module, package, or interface compiles on its own into class-level artifacts, and instantiation, parameter binding, and hierarchy all happen when the simulation starts. Compile time then follows how many distinct units a design has, not how many instances it elaborates into.

Those commitments, and the constraints that follow from them, are stated in docs/architecture/north_star.md. Every other design document in this repository answers to that one.

Coverage is measured rather than described. Every construct Lyra handles is claimed by a case under tests/conformance/ stating what IEEE 1800 requires of a program and checking itself…

score = signal / reach signal = 0.25·commit_velocity // commits in last 90 days (cap 30) + 0.20·contributor_work // unique authors × velocity (cap 100) + 0.20·issue_resolution // closed ÷ total issues + 0.20·fork_ratio // forks ÷ stars (proxy for real usage) + 0.10·release_cadence // releases in 90 days (cap 3) + age_bonus // +0 to +0.30 after 6 months + homepage_bonus // +0.05 if homepage is set reach = log₁₀(stars + watchers + 10)█

health = 0.35·recency // days since last commit (90d decay) + 0.25·cadence // commit rhythm consistency + 0.20·issue_health // closed ÷ total issues + 0.20·pr_health // merged ÷ total PRs█

Healthy 80 – 100 active, responsive, regular releases Stable 60 – 79 maintained, steady, no alarms Quiet 40 – 59 slowing down — watch this one At Risk 0 – 39 going dark · candidate for rescue█

solo_builder one person holds > 80% of commits (last 180d) needs_contributors has open "help wanted" or "good first issue" labels hidden_gem < 100 stars · active in last 3 months · documented legacy_hero repo > 5 years old · committed this year fork_magnet forks/stars > 0.5 · used as template or dependency release_machine 5+ releases in the last 90 days under_pressure > 10 open issues · ≤ 2 contributors · health ≥ 60 community_watch watchers > stars · devs tracking before the public community_hub GitHub Discussions enabled · > 20 discussions funded maintainer has active funding channel█