Free & open source
Tools for the test bench, built by someone who's on it.
OpenBench makes free, source-available utilities for test and automation engineers — no license key, no telemetry, no procurement cycle. First up: a Modbus simulator.
modbus-sim — TCP:502 — slave id 1
Why open source, why free
01 — Audit-able
Source is public. If your company requires code review before a tool touches an engineering workstation, that's a five-minute conversation instead of a blocker.
02 — Built by practice
Every tool here comes from a real gap on a real bench — test, measurement, and automation work, not a hobby guess.
03 — No paywall to try it
Local functionality stays free, always. If you get value from it and want to support the work, there's a donate link — never a requirement.