5. NL5 - "Concept Simulation" tool

This is an excerpt from NL5 presentation:

Concept Simulation is a process where design ideas are evaluated and iterated using fast and simple simulation tool. The result of this process is a schematic which is more complete and is ready for the rigorous and detailed SPICE simulation. This allows your SPICE simulation stage to be shorter and much more efficient.

In the Concept Simulation stage many iterations are performed in a short period of time, concurrent to the engineer’s thinking. A tool used for Concept Simulation should provide the
response extremely fast, preferably before the next idea comes into engineer’s mind. It needs to allow instantaneous modification of the design and starting of a new simulation with minimal delay. Under no circumstances should the simulator be a frustrating “bottleneck” in the process. The Concept Simulation tool must complement the engineer’s thinking, literally being a seamless and efficient add-on to the engineer’s brain.

NL5 meets all of these requirements well: it is easy to use, fast, and reliable, substantially due to its ability to work with ideal components.