Not sure how this website is legal, but it exists. There are thousands of project files, some are for laser cutter while others are for CNC. It’s almost like Pinterest for ideas but you actually can get the files needed to make the project.
Laser cutters can use almost any 2D file type but the most common are vector files. Bluevertigo is a weird site but offers a curated list of free sites that carry vector files that can be easily modified for machine use.
Boxes.py is an Open Source box generator written in Python. It contains both ready-made parameterized generators and Python API for writing your own.
ChiliPeppr is a hardware fiddle, meaning it is a website that lets you easily create a workspace to fiddle with your hardware from software. ChiliPeppr provides a Serial Port JSON Server that you run locally on your computer, or remotely on another computer, to connect to the serial port of your hardware like an Arduino or other microcontroller. Then you write widgets in Javascript that interact with your hardware by forking the base template widget or forking another widget that is similar to what you are trying to build.
ChiliPeppr's Serial Port JSON Server is the basis for the Arduino's new web IDE.
LaserWeb / CNCWeb 4.0 is an application for generating GCODE from DXF/SVG/BITMAP/JPG/PNG files for Lasers and CNC Mills and controlling a connected CNC / Laser machine that’s running one of the supported firmware.
OpenBuilds is an application for connecting to and controlling, your CNC machine. Compatible with GRBL, smoothiboard, and others. Looks and feels professional. A new personal favorite.