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

Syntax highlighting not supported for 'plantuml', see HelpOnParsers.

   1 @startuml
   2 class Car
   3 
   4 interface ICar{
   5     addWheel(Wheel w)
   6 }
   7 
   8 note "This is a floating note" as CarNote
   9 CarNote .. Car
  10 
  11 Driver - Car : drives >
  12 Car *- Wheel : have 4 >
  13 Car -- Person : < owns
  14 
  15 /' 
  16 <|--  extends 
  17 -- association
  18 ..> depends 
  19 <|.. implements / realizes
  20 '/
  21 
  22 Car ..|> ICar 
  23 Car : engine : String
  24 Car : startEngine() 
  25 
  26 @enduml