Installing PlantUML

On Debian and derivatives, PlantUML can be installed with apt:

sudo apt install plantuml

The version in Ubuntu 24.04 LTS is: 1.2020.2. This version includes the C4 diagrams in the so-called PlantUML Standard Library:

plantuml -version
plantuml -stdlib | grep -A2 'c4'

To test that it has been set up correctly, create a simple diagram definition:

cat > diag.puml <<EOF
@startuml
Alice -> Bob: test
@enduml
EOF

Generate the corresponding diagram in SVG format:

plantuml -tsvg diag.puml
xdg-open diag.svg

This version of PlantUML still uses the “rose” theme and does not yet support the -theme option. But it is possible to render the diagram in black & white:

plantuml -Smonochrome=true diag.puml

Vim setup

To set up filetype detection, syntax highlighting, and the makeprg variable, install the aklt/plantuml-syntax plugin:

mkdir -p ~/.vim/pack/plugins/start/
cd ~/.vim/pack/plugins/start/
git clone https://github.com/aklt/plantuml-syntax

Change the default output format from PNG to SVG with:

cat >> ~/.vimrc <<END
let g:plantuml_executable_script = 'plantuml -tsvg'
END

You can then generate the diagram for the file you’re editing from within Vim by simply running :make.