Calspex - Calibration
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
QMSys GUM - Calibration
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
QC-Pro Gage Management - Gage Calibration Management, Measurement System Analysis, GRR, SPC, Equipment Maintenance, Employee Training Log, Product Test Management
QUCS - Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit.