Oregano is a Scripts software developed by Richard Hult. After our trial and test, the software is proved to be official, secure and free. Here is the official description for Oregano:

BS Editor: Oregano has an user friendly graphic interface that allows to design and describe the circuit to simulate. It provides a wide variety of component libraries, including CMOS, TTL, lineal, operational amplifiers, and a lot more!

Oregano lets you simulate the designed circuits. You can analyze in time, in Frequency, do DC sweep and Fourier Analysis. You can configure several simulation options, use Probe tools, edit the netlist and simulate manually.
Oregano can use GNU Cap and ngSpice as simulation backends.

The main goal is to develop a program that is easy to use, it does not encumber the user with lots of unnecesary options, and that anyone can use it with very little effort.