Electronics domain involves a lot of skills starting from basic device and circuit simulations, to PCB design, micro controllers and a complete IoT system implementation. Hence, for any beginner it is necessary to explore the open source tools and software that can be utilised for skill development, concept building and learning with hands on experience.
Octave : For mathematical equations, Matlab basics, numerical computation, plotting graphs, matrices, linear and non linear algebra, Differential equations etc.
EAGLE / Fusion 360: For complete overview of PCB design concept, component integration, placement, design and routing frameworks.
Arduino : One of the basic and most widely used micro controller by electronics engineers. Arduino IDE platform allows C / C++ based programs for controller operation and its simulation on the hardware. Arduino provides a large set of inbuilt examples to allow the learners about sensor interfacing and other basics easily.
Proteus : Proteus design suite allow to design the circuit schematic on breadboard based approach. It is widely useful for beginner to simulate the desired circuits on software prior to actual hardware implementation.
QUCS : Quite Universal Circuit Simulator is another widely used tool for design of circuit level schematics including transistors, operational amplifiers, and other electronic components to design and verify basic concepts.
LTSPICE : Linear Technology SPICE is the freely available tool for circuit simulation with DC, AC, transient analysis for various electronic devices. It is exceptionally tool for beginners who can add on their skill set and get to advanced tool such as HSPICE.
Xilinx : Xilinx ISE (Integrated Synthesis Environment) is useful for digital electronics engineers working with VHDL / Verilog language and FPGA hardware. Xilinx provides synthesis, area, power, timing analysis for coded digital logic block along with RTL view.