CodeShare.io - Realtime code sharing for developers
Code2Flow - An easy solution to create product flows.
Snipper.io - Collaborate with your friends on the same code in real time
Flowchart.js - Draw SVG flow charts from simple text representations of the diagrams.
DIagrams Through Ascii Art - Java command-line tool to convert ASCII diagrams to bitmaps.
Marmoset - Create gorgeous code snapshots.