Code2Flow - An easy solution to create product flows.
CodeShare.io - Realtime code sharing for developers
DIagrams Through Ascii Art - Java command-line tool to convert ASCII diagrams to bitmaps.
Flowchart.js - Draw SVG flow charts from simple text representations of the diagrams.
codepad - Very simple webpage with a simple textbox, a checkbox for selecting one of several languages and an...
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.