DRAKON Visual Language
DRAKON is a visual language for specifications from the Russian space program. DRAKON is used for capturing requirements and building software that controls spacecraft.
The rules of DRAKON are optimized to ensure easy understanding by human beings.
DRAKON is gaining popularity in other areas beyond software, such as medical textbooks and law. Its purpose is to represent any knowledge that explains how to accomplish a goal.
About the DRAKON language: DRAKON.pdf
DRAKON in functional programming: DRAKON-Erlang
ERIL, DRAKON's counterpart for structure diagrams: The ERIL Language
DRAKON fits well for describing behaviour with state machines (finite automata): State Machines in DRAKON Editor