ngspice-jit is a fork of ngspice (the mixed-level/mixed-signal circuit
simulator) aimed at running raw foundry analog / mixed-signal top-level
chips without hand-conversion.

Its headline feature, and its name, is that it JIT-compiles the
behavioral R/C value expressions a PDK writes
(voltage/temperature-dependent poly-resistors, MIM capacitors,
high-field tanh laws) into native OSDI devices at parse time, so the
solver sees real charge/current-conserving devices instead of fragile
behavioral sub-circuits.  It also adds Eldo-style topology reduction
(dangling-passive removal), regular-expression selection in
show/display/print/plot/write/save, a new 'devices' command, and
assorted fixes.

The startup banner is tagged "[ngspice-jit fork: ...]" so the binary is
distinguishable from a stock ngspice at a glance. The internal simulator
name and version stay "ngspice-46" so .raw files remain compatible.

The OSDI codegen invokes the system compiler (gcc) at run time; gcc is
part of the Slackware base system.  The osdi headers it needs are
installed to /usr/share/ngspice/osdi and spinit is set to find them.

Documentation shipped under /usr/doc/ngspice-jit-VERSION:
examples         - the upstream example-circuit tree (from the source)
reference_manual - our HTML/PDF command reference (ngspice_manual.html /
                   .pdf, tested vs ngspice-46), carried by the source
                   tarball.

Important: Installing ngspice-jit will overwrite the original ngspice
executable and all the libraies name are the same.

Homepage: https://codeberg.org/alto555/ngspice
