- [AxiDraw](https://shop.evilmadscientist.com/productsmenu/846) - Pen plotter from [Evil Mad Scientist](https://www.evilmadscientist.com), very popular on [#plottertwitter](https://twitter.com/hashtag/plottertwitter).
- [Line-us](https://www.line-us.com) - A cute little kickstarted robotic drawing arm.
- [WaterColorBot](https://watercolorbot.com) - XY art robot and software to plot with watercolor paints.
- [EggBot](https://egg-bot.com) - Pen plotter for egg-shaped and spherical objects.
- [HP Pen Plotters](https://www.hpmuseum.net/exhibit.php?class=4&cat=24) - Vintage desktop and floor-standing pen plotters from the creator of the HPGL standard. Model 7475A is very common and can usually be found on eBay.
- [BrachioGraph](https://brachiograph.readthedocs.io/en/latest/) - A cheap and simple plotter made from sticks, servos, and a Raspberry Pi running Python.
- [grblShield](https://github.com/synthetos/grblShield) - All the stepper motor control hardware needed to turn an [Arduino](https://www.arduino.cc) into a G-code-based motion controller using the grbl firmware. ([adafruit](https://www.adafruit.com/product/1750))
- [TinyG](https://github.com/synthetos/TinyG) - More featureful and robust 6-axis G-code-based motion control hardware. ([adafruit](https://www.adafruit.com/product/1749))
- [Arduino CNC Shield](https://blog.protoneer.co.nz/arduino-cnc-shield) - Grbl-compatible stepper motor control shield for Arduino, similar to the [grblShield](https://github.com/synthetos/grblShield).
- [Raspberry Pi CNC Hat](https://wiki.protoneer.co.nz/Raspberry_Pi_CNC) - Raspberry Pi add-on board w/ stepper controllers and a microcontroller running grbl. Interfaces with the Pi's serial pins.
- [Plotter Cable Pinout](http://sites.music.columbia.edu/cmc/chiplotle/plotter_cable.pdf) - Schematic for a plotter cable that will work for most HP and Roland plotters. Search eBay or Amazon for `DB9 to DB25 Serial Null Modem Cable` or similar to find them for sale.
- [Sharpie Fine Point Plotter Adapter](https://www.thingiverse.com/thing:229982) - 3d-printed adapter to fit a standard Sharpie in an HP-GL plotter.
- [Parametric 3d-Printable Plotter Pen Adapter](https://openjscad.org/#https://gist.githubusercontent.com/beardicus/d668c0f6b96be53d16dc/raw/plotter-pen-adapter.jscad) - Adjustable model to print adapters for various pens.
- [Plotter Pen STL Models](https://www.thingiverse.com/thing:227985) - Accurate STL models of both short and long standard plotter pens.
- [Pens for AxiDraw](https://wiki.evilmadscientist.com/Pens_for_AxiDraw) - List of pens suitable for general plotter abuse.
- [Pens for EggBot](https://wiki.evilmadscientist.com/Pen_choices) - Egg- and glass-focused pen recommendations but still generally applicable information.
- [JetPens – The Best White Ink Pens](https://www.jetpens.com/blog/the-best-white-ink-pens/pt/340) - A comprehensive review of many white ink pens, with pictures of their coverage characteristics.
- [HPGL Reference Guide](https://www.isoplotec.co.jp/HPGL/eHPGL.htm) - HTML-based HPGL Reference.
- [HP 7475A Interfacing and Programming Manual](https://archive.org/details/HP7475AInterfacingandProgrammingManual) - Scanned PDF manual that contains a full HPGL reference.
- [djipco/hpgl](https://github.com/djipco/hpgl) - A Node.js library to communicate with HPGL-compatible plotters and printers.
- [hp2xx](https://www.gnu.org/software/hp2xx) - GNU tool to convert HPGL into other vector and raster formats. Can also be used as a previewing in X11.
- [vec](https://github.com/anachrocomputer/vec) - Example C code for generating HPGL, with a turtle graphics interface.
- [d3-hpgl](https://github.com/aubergene/d3-hpgl) - An adapter for the HTML Canvas API so you can output HPGL using the popular [D3](https://d3js.org) library.
- [HPGL Viewer](https://github.com/drskullster/HPGLViewer) - An HPGL Viewer using JavaScript and HTML5 canvas.
- [HPGL Sender](https://github.com/LgHS/hpgl-sender) - A web interface for previewing HPGL and sending it to your plotter.
G-code is a text-based standard for controlling CNC machines. Though it was designed for industrial machines, its use in many hobbyist 3d printer firmwares has made it ubiquitous in small-scale DIY projects as well.
- [axidraw](https://github.com/evil-mad/axidraw) - Official AxiDraw extensions for Inkscape.
- [axi](https://github.com/fogleman/axi) - Unofficial Python library for the AxiDraw v3.
- [xy](https://github.com/fogleman/xy) - Utilities for the Makeblock XY Plotter Robot Kit.
- [LaserGRBL](https://github.com/arkypita/LaserGRBL) - Laser-optimized Windows GUI for grbl controllers. Could be repurposed for DIY pen plotters that use a solenoid for pen up/down movements.
- [Line-us Inkscape Plugin](https://github.com/Line-us/Inkscape-Plugin) - Sends drawings to the [Line-us plotter](https://www.line-us.com) directly from Inkscape.
- [Line-us API Examples](https://github.com/Line-us/Line-us-Programming) - Example code for the [Line-us](https://www.line-us.com) plotter's G-code-based API.
- [@beardicus/line-us](https://github.com/beardicus/line-us) - JavaScript library for controlling the [Line-us](https://www.line-us.com) machine from Node or the browser.
- [PenPlotter](https://github.com/RickMcConney/PenPlotter) - Polargraph controller that uses repetier firmware.
- [Makelangelo-firmware](https://github.com/MarginallyClever/Makelangelo-firmware) - Firmware for the Makelangelo polargraph robot.
- [RoboPaint](https://github.com/evil-mad/robopaint) - Software for the WaterColorBot.
- [AxiTurtle](https://github.com/ralphcrutzen/AxiTurtle) - Turtle graphics for AxiDraw in Processing.
- [GRBL-Plotter](https://github.com/svenhb/GRBL-Plotter) - Plotter-optimized Windows GUI for grbl controller with SVG and DXF import, and flexible pen up/down control.
- [saxi](https://github.com/nornagon/saxi) - Driver and library for the AxiDraw. Uses constant-acceleration motion planning and automatically resizes to paper.
- [MP2300-Tools](https://github.com/Jan--Henrik/MP2300-Tools) - Software for converting HPGL to Graphtec's GPGL format, as well as CAD files for a Graphtec plotter pen adapter.
- [SquiggleDraw](https://github.com/gwygonik/SquiggleDraw/commits/master) - "SquiggleDraw will create a SVG file from an image, using the brightness to change the amplitude of sine waves".
- [svgurt](https://svgurt.com) - Web-based PNG to SVG creative noodler.
- [maptrace](https://github.com/mzucker/maptrace) - Produce watertight polygonal vector maps by tracing raster images.
- [Drawbot_image_to_gcode_v2](https://github.com/Scott-Cooper/Drawbot_image_to_gcode_v2) - Creates G-code for use on drawbots.
- [blackstripes](https://github.com/fullscreennl/blackstripes-python-extensions) - Turns a PNG image into a SVG line drawing.
- [Ribbon](https://github.com/fogleman/ribbon) - Ribbon diagrams of proteins in written in Go.
- [penplot](https://github.com/mattdesl/penplot) - A development environment for plotter art in JavaScript.
- [penkit](https://github.com/paulgb/penkit) - A Python library for creating line-based SVG graphics.
- [generativeExamples](https://github.com/digitalcoleman/generativeExamples) - Example Processing code that generates plottable PDFs.
- [Let's make map](https://svg-exporter.netlify.com) - Web-based tool to export an SVG map from Mapzen tiles.
- [SuperformulaSVG for web](https://jasonwebb.github.io/SuperformulaSVG-for-web) - A generative line art web app.
- [scribbleplot](https://github.com/bleeptrack/scribbleplot) - Scribbly image transformations in Processing.
- [Maker.js](https://maker.js.org) - Library for creating 2D vector drawings for CNC and laser cutter machines.
- [Turtletoy](https://turtletoy.net) - Browser-based JavaScript turtle graphics API with SVG export.
- [svgsort](https://github.com/inconvergent/svgsort) - Path planning for plotting SVG files, reduces time spent moving with the pen up.
- [svgo](https://github.com/svg/svgo) - Node.js-based tool for optimizing SVG files.
- [Polargraph Optimizer](https://github.com/ezheidtmann/polargraph-optimizer) - Optimize drawing plan for a polargraph.
- [penkit-optimize](https://github.com/paulgb/penkit/tree/master/optimizer) - An SVG optimizer that uses a vehicle routing solver to minimize plot time.
- [svg-crowbar](https://github.com/NYTimes/svg-crowbar) - Chrome-only bookmarklet for extracting SVG from an HTML document.
- [Summary of single line fonts](http://imajeenyus.com/computer/20150110_single_line_fonts/index.shtml) - Good information and links to other resources and fonts.
- [Hershey Vector Font](http://paulbourke.net/dataformats/hershey) - `.fnt` format of vector fonts from the 60s. Includes a good overview of the original data format of the fonts.
- [hershey-fonts](https://github.com/kamalmostafa/hershey-fonts) - C library and original font data for the Hershey fonts.
- [OneLineFonts.com](https://www.onelinefonts.com) - Commercial site with some single-line fonts available for purchase.
- [An Intro to Pen Plotters](https://medium.com/quarterstudio/an-intro-to-pen-plotters-29b6bd4327ba) - Good info on getting started with old HPGL plotters.
- [1980s pen plotters of the future](https://notes.variogr.am/2012/08/12/1980s-pen-plotters-of-the-future) - Another intro to vintage pen plotters.
- [Pen Plotter Programming: The Basics](https://medium.com/@fogleman/pen-plotter-programming-the-basics-ec0407ab5929) - Some basics of programming vector paths, including sorting, joining, and simplifying.
- [Roland DG DXY-990](https://hackaday.io/project/12276-roland-dg-dxy-990) - Quickstart guide for a Roland flatbed plotter.
- [The Cohen-Sutherland Line Clipping Algorithm](https://sighack.com/post/cohen-sutherland-line-clipping-algorithm) - Detailed explanation and examples of an interesting algorithm.
- [Vera Molnár](https://www.surfacemag.com/articles/vera-molnar-in-thinking-machines-at-moma) - OG plotter artist.
- [Hektor](http://juerglehni.com/works/hektor) - The original cable-based drawbot from 2002.
- [Surface Projection](https://bitaesthetics.com/posts/surface-projection.html) - Deep dive into surface projection and hidden line removal using Python and penplot.
- [Chiplotle-discuss](https://lists.columbia.edu/mailman/listinfo/chiplotle-discuss) - Fairly inactive mailing list for the Chiplotle HPGL Python library with some general plotter talk.
To the extent possible under law, [Brian Boucheron](https://boucheron.org/brian) has waived all copyright and related or neighboring rights to this work.
