pm: a simple, cross-platform system package manager

pm exists amid a set of trade-offs in distributing software. The ideas behind pm were born at a time when:

• There was no overlap in the Venn diagram of system package managers that offered both strong security promises (signed packages) and permissive licensing (most are GPL).
• There was reason to suspect that Unix systems might be shipped without scripting languages; software like brew would cease to work and engineers would be left without a way to fetch and install software.
• Engineers wanted to deploy software to a variety of Unix-like environments using a single system.
• Engineers wanted a simple-to-reason-about system that used familiar Unix primitives as building blocks to distribute their software.

Simplicity is a principal design goal of this project. When offered an opportunity to chose between two designs the design that requires less mental scaffolding to describe or implement should be used. As a concrete example: transitive dependency calculations are implemented, but supporting compatible version ranges are not.

The project is currently in early design phases, and this document describes the high-level approach of the project.