License Test Suite

This document sets out a list of well known projects, placed in a loose taxonomy, that serve as a checklist when drafting public software license terms. When thinking about how a new license will work when applied to different kinds of software, running through this list can help.

This list can also serve as a research list for lawyers without technical backgrounds, who need to develop a sense of the kinds of software available.

Last Updated: February 2, 2022

We can think of software projects as falling into a few general categories and subcategories.

Skip To: Applications Components Development Tools Platforms

Applications

meet a particular, non-technical need for end-users

Standalone Applications

provide all the functionality needed to meet the end-user need

Examples:

• Inkscape, a vector-image editor

• Signal, a secure messaging application

Plugins

add more functionality to larger applications

Examples:

• Adblock Plus, a web browser extension that blocks advertisements on webpages

Server Applications

provide a server for client applications to contact

Examples:

• NGINX, a web server

• WordPress, a web content management system

Client Applications

contact server applications

Examples:

• Firefox, a web browser

Peer-to-Peer Applications

act as both clients and servers

Examples:

• BitTorrent, a file sharing application

• Ethereum, a peer-to-peer, blockchain-based processing system

Components

are used to build applications

Libraries

provide code for developers to invoke

Examples:

• jQuery, a front-end JavaScript toolkit and compatibility layer

• mongo-c-driver, a C driver for the MongoDB database

• OpenSSL, a cryptography and SSL/TLS toolkit

Frameworks

invoke code that developers write

Examples:

• Ruby on Rails, a server-side web application framework

• Ember, a full-stack web application framework

• Cordova, a mobile application framework

Services

communicate with other programs

Examples:

• PostgreSQL, a SQL database

• Network Time Protocol Daemon, a system daemon that synchronizes system clocks

Development Tools

help developers make software

Editors

are the applications programmers use to write code

Examples:

• Emacs, a highly extensive text editor

• Eclipse, a highly extensive integrated development environment

Generators

output source code

Examples:

• Bison, a parser generator

• WebPack, a front-end JavaScript bundler

• UglifyJS, a JavaScript minifier

• Obfuscar, an obfuscator for .NET assemblies

Analyzers

take source code as input, and output useful information

Examples:

• ESLint, an extensible linter for JavaScript

• Frama-C, a C-language analyzer toolkit

Compilers

take source code as input, and output binary code

Examples:

• GCC, a compiler for several languages

• LLVM, a compiler for several languages

Debuggers

help programmers run programs step-by-step

Examples:

• GDB, a C debugger

Package Managers

download and install software components

Examples:

• npm, a package manager for JavaScript

• RPM, a Linux system package manager

Revision Control Systems

manage changes to source code over time

Examples:

• Git, a distributed version control system

• GitLab, an integrated source code management system

Platforms

help users run applications

Kernels

makes computer hardware available for computer software to use

Examples:

• Linux, a UNIX-like operating system

Base Systems

perform small tasks from the command line

Examples:

• GNU coreutils, a collection of core UNIX utilities

• BusyBox, a collection of core UNIX utilities for embedded systems

Interpreters

run programs written in interpreted languages

Examples:

• Python, a programming language interpreter

Orchestrators

set each each part of an application up to be run, and connect them together

Examples:

• Chef, a configuration management tool

• Kubernetes, a container-based orchestration system