PlantUML

https://en.wikipedia.org/wiki/PlantUML

wget http://vorboss.dl.sourceforge.net/project/plantuml/plantuml.jar
java -Djava.awt.headless=true -jar ~/Downloads/plantuml.jar sequence1.txt
requires graphviz (dot)
http://plantuml.com/class-diagram
java -Djava.awt.headless=true -jar ~/Downloads/plantuml.jar class1.txt

Class diagram

@startuml
class Car

interface ICar{
    addWheel(Wheel w)
}

note "This is a floating note" as CarNote
CarNote .. Car

Driver - Car : drives >
Car *- Wheel : have 4 >
Car -- Person : < owns

/' 
<|--  extends 
-- association
..> depends 
<|.. implements / realizes
'/

Car ..|> ICar 
Car : engine : String
Car : startEngine() 

@enduml