PlantUML

1. Install

Pull docker image.

  
$ docker pull plantuml/plantuml-server:jetty

Run container.

  
$ docker run -d -p 8080:8080 plantuml/plantuml-server:jetty

2. Diagrams

2.1. Sequence Diagram

  
@startuml

hide footbox
title Sample Sequence

participant Alice
participant Bob

Alice -> Bob:   Request
Bob --> Alice:  Reply

@enduml

2.2. Class Diagram

  
@startuml

class Dummy {
    filed1
    method1()
}

@enduml

2.3. Activity Diagram

  
@startuml

start

if (Graphviz installed?) then (yes)
  :process all\ndiagrams;
else (no)
  :process only
  __sequence__ and __activity__ diagrams;
endif

stop

@enduml

2.4. Gantt Diagram

  
@startgantt
Project starts 2020-07-01
[Prototype design] starts 2020-07-01 and ends 2020-07-15
[Test prototype] starts 2020-07-16 and requires 10 days
@endgantt

2.5. Yaml

  
@startyaml
doe: "a deer, a female deer"
ray: "a drop of golden sun"
pi: 3.14159
xmas: true
french-hens: 3
calling-birds: 
    - huey
    - dewey
    - louie
    - fred
xmas-fifth-day: 
    calling-birds: four
    french-hens: 3
    golden-rings: 5
    partridges: 
        count: 1
        location: "a pear tree"
    turtle-doves: two
@endyaml

References

plantuml.com