simutron

Electronic circuit simulator.
Simple environment to run and debug firmware for AVR 8-bit microprocessors.
Able to run arduino firmware.
Internally this program uses the open source Simavr AVR Processor Simulator (https://github.com/buserror/simavr) and wraps all its functions in a GUI shell. Setups for firmware debugging scenarios can be created dynamically. Able to run 16MHz MCU with decent set of external parts in real time. In particular this can be used for development of CNC firmware in conjuction with its CAM frontend without access to the real hardware.
For Linux and Windows systems.
Please visit wiki pages (https://sourceforge.net/p/simutron/wiki/Home/) for instructions

Today’s small-to-medium-sized (SMB) businesses and large enterprises are saving on their monthly communications costs by making one simple decision: to switch to a VoIP service solution from their old, outdated Plain Old Telephone Service (POTS). By choosing a new VoIP service, these companies enjoy the flexibility, reliability, call features, and audio quality that only a VoIP service can provide. Plus, they cut their phone bill by up to 70%!