The core of the package is rather stable now but some of the user interface macros (most of them are just syntactic sugar) still need a better design. Right now mpcirc supports two distinct programming styles for drawing diagrams: turtle-based, and node-based. In the first one you draw a wire from one point to another, then place an element at its end, then continue at its other end and so on. In the node-based approach the node locations are determined first and then the elements are put between them using betw.x macros.
This second approach arised as I developed a program for automatic conversion from the PSPICE .cir files to the mpcirc format programs.
Some of the element designs were adapted from the circ package.
Some general usage remarks:
A primitive PSPICE to mpcirc converter spice2circ (written in Perl5) is also available.
You can also grab a mpcirc.tar.gz tar file containing the whole directory.
This page (http://ci.uofl.edu/tom/software/LaTeX/mpcirc/) was most recently modified on Aug 6, 19101.