NCH Swift Sound
Axon is a virtual IP PBX for Windows designed to manage phone calls.
ShenZhen X&Y Communication Technologies Co.,Ltd PRC
Provides rich features for business telephony communications requirement.
It is designed for the entry or hybrid VoIP or IP PBX market space.
DCS Laboratory Ltd.
Call accounting application for office telephone switching systems. Free demo.
New Wave Concepts Limited
Combines circuit design, simulation and CAD manufacture to realize projects.
Draw electrical circuit diagrams and PCB netlist files.
Moeller GmbH, Rockwell Automation Inc.
This program will help you simulate circuits including Pico controllers.
the Qucs team
Quite Universal Circuit Simulator is an integrated circuit simulator.
University of Colorado
Build circuits with resistors, light bulbs, batteries, and switches.
Circuit Magic is an electrical circuits simulation program.
EASY-SOFT is a graphic editor for representation of the circuit diagram.
The RUPLAN system enables editing of circuit diagram.
Festo Didactic GmbH & Co. KG
FluidSIM 5 is a circuit diagram design and simulation program.
It's a software tool created to assist teaching basic digital circuit concepts.
AUTOMSIM is a circuit design and simulation software for digital electronic.
WinBreadboard is designed to manipulate chips and wires for a digital circuit.
Simulo is a program which simulates the operation of a digital circuit.