EasyEDA - EasyEDA - Web-based EDA suite; runs in browser.
Cisco Packet Tracer - Download Cisco Packet Tracer, an innovative network simulation and visualization tool used by Cisco Networking Academy students and instructors.
LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
TINACloud - Create Simulate and Design Circuits and their PCB layout with TINACloud
GNS3 - GNS3 is a graphical network simulator that allows simulation of complex networks.