D2 is a modern diagramming language that allows users to create customizable diagrams quickly using simple syntax. It supports multiple languages, animations, and various features like Markdown integration, local CLI, and exports, making it suitable for academic and professional use. The tool also includes an online playground and official support for popular editors like VSCode and Vim.

Bluefish allows users to create complex diagrams by combining simpler components such as alignment, spacing, and arrows. It comes with built-in graph and arrow layouts, while also offering the flexibility to implement custom layouts.