Tools and Utilities

Documentation Aids

Doxygen http://www.stack.nl/~dimitri/doxygen
Graphviz (use with Doxygen) http://www.graphviz.org/
Message Sequence Charts http://www.mcternan.me.uk/mscgen/
Block and Sequence Diagrams http://blockdiag.com/en/blockdiag
Wavedrom (digital timing diagrams) http://wavedrom.com
ASCII Flow Charts http://asciiflow.com/
ASCII Circuit Diagrams http://www.tech-chat.de/ascii-circuits.html
Mind Mapping http://freemind.sourceforge.net/
Mind Mapping + more http://freeplane.sourceforge.net

Utilities

Embedded System Console http://www.umonfw.com/ucon/
Log File Analysis http://casstor.com/about/logfilter/
Hex File Editor http://www.hhdsoftware.com/free-hex-editor
SD Card Formatter https://www.sdcard.org/downloads/formatter_4/
IR Protocol Analyser http://www.analysir.com
Graphing Calculator http://www.desmos.com

Text Editors

Notepad++ https://notepad-plus-plus.org

Programming Languages

Pelles C http://www.smorgasbordet.com/pellesc/
Ragel (Finite State Machine Generator) http://www.colm.net/open-source/ragel/
Code Formatting http://astyle.sourceforge.net/
Create Header Files http://www.hwaci.com/sw/mkhdr/