Salut is a small program that performs calculations on simple networks around two-port devices (like transistors) characterized by s-parameters, at radio frequencies.

The main advantage over many other simple microwave/rf simulation programs is that it has the possibility to model components in series with a two-port block. This is interesting since some reactance to ground will always be present in every application. Salut is also not restricted to the usual common emitter or common source configuration even though many semiconductor manufacturers only provide s-parameters for this case.
 
With Salut, it is easy to look for negative resistances in oscillator circuits.

Salut is a command line only program, written in C to run under linux/unix.
If someone prefers to use it in a less flexible environment it should be very easy to port.

Documentation is included as a README-file in the tarball.
There are also some examples available of how to use the program.

Salut version 1.0.1 by Daniel Uppström, August 2005, released under the GNU GPL:
salut-1.0.1.tar.gz
md5sum: 7d7ac4c50136c09435e01a85976ac1a8

Any feedback or comments is appreciated.

There is also a freshmeat project page.