The following are tools for performing various transformations and processes to G-Code.
Note that if using MeshCAM with a Carbide 3D Nomad license you will need to open the file in Carbide Motion while connected to the machine and export it in unencrypted format in order to use any sort of post-processor.
|Utility (Windows)||GCodeTruncater||Windows tool to trim too long decimals from G-code. Download link|
|Utility (Python)||metric-gcode-truncator||Python tool to trim too long decimals from G-code.|
|Utility (CLI)||grecode||Opensource command line utility to shift, rotate, mirror and align gcode.|
|Utility||G-Code Scaling Tool||Scaling.|
|Utility||WarpDriver||Windows program to warp a G-code file to match a pre-defined shape.|
|Utility||i-Logic's page of utilities||Shift, Rotate NC Code, NC to CAD, Cone Calculator and Rotation Calculator.|
|Utility||MakerCam and Inkscape Post-Processor||Post-Processor.|
|Utility (Ubuntu 13.04 x64)||GCodePostProcessor||Features include:
|Utility (GUI)||G-Code Ripper||Read, Scale, Rotate, Split and Wrap G-Code. Also able to convert G-code to DXF: http://www.scorchworks.com/Blog/g-code-to-dxf-with-g-code-ripper/ |
|Utility (GUI)||CNC Tools||Toolset written in java to work on, transform, create (like a wizard/toolbox) and visualize G-Code.|
|Utility (Perl)||G-code Converters||Perl program for post-processing a file which contains G83 canned drill cycle commands.|
|Utility (Windows)||G-code Optimizer||A command-line tool that optimizes CNC Mill and Laser Engraver gcode generated from programs like MakerCAM - also optionally converts mill gcode to laser gcode.
Can reduce time to a third.
|Optimize (opensource)||gcodemillopt||gcodemillopt is Open-Source software which will optimize gcode produced by software like MakerCAM. It does this by arranging gcode so that cutting operations are ordered to minimize the distance between cuts. When used with the -laser option it will convert G1 Z and G0 Z codes to M3 and M5 codes to turn on and off a laser instead of moving the Z axis. Written in open source C++ it should compile on most platforms. A 32-bit Windows binary is available in github along with the source code. If renamed to gcodelaseropt the -laser flag is enabled automatically.|
|Optimize||PCB G-code Optimizer||Optimizes G-code for milling PCB. Maybe can be used also for optimizing other G-codes.|
https://github.com/mythagel/nc_tools --- A collection of composable CNC/CAM GCode tools
http://www.thingiverse.com/thing:407580 --- Python program to make g-code compatible for Mach3 or Linuxcnc
https://github.com/FormerLurker/ArcWelderLib --- utility for converting G1 straight-line moves to G2/G3 arc moves
https://github.com/md8n/GCodeClean --- A library and command line utility to do some 'cleaning' of a gcode (an .nc, .gcode) file. The primary objective is to be a GCode Linter, per line linting of gcode is already done. 
In a class by itself is: https://www.ultimatesolver.com/en/midi2gcode