proofpack is a $\LaTeX$ package to typeset natural deduction proofs (in mostly a Fitch-style way). It is most similar to fitch.sty by Johan W. Klawer (June 10, 2001) and edited by Alexander W. Kocurek (June 8, 2019). It deviates from this package in several ways, but notably it allows for simpler input. The simpler input makes it more attractive to those new to $\LaTeX$ and for students learning logic.

Download the proofpack.sty file to the directory where you keep your $\LaTeX$ packages. You can then use the package by adding the following line to the preamble of your $\LaTeX$ document:

\usepackage{proofpack}

Here is a video overview that covers the absolute basics (intended for beginners to $\LaTeX$ and students).

See proofpack.pdf for documenation and usage.