A restartable sequence is a critical region delimited by a program where if its execution is preempted or interrupted, the kernel will divert the program control flow to a defined abort handler. They are a good alternative to atomic operations for critical fast paths and are usually used in the context of per-cpu data. The library offers ABI headers to interface with the kernel and various utilities such as per-cpu counters.

Lib3ds is a toolkit for handling the 3DS format for 3D model files. Its main goal is to simplify the creation of 3DS import and export filters.

Capstone is a lightweight multi-platform, multi-architecture disassembly framework. Capstone can disassemble machine code for many supported architectures such as x86, x86_64, arm, arm64, mips, ppc, sparc, sysz and xcore. It provides bindings for Python, Java, OCaml and more.

Candle is a GRBL controller application with a visualizer for G-Code, the CNC programming language.

Supported functions include:

• Controlling GRBL-based cnc-machine via console commands, buttons on form, numpad.

• Monitoring CNC-machine state.

• Loading, editing, saving and sending of G-code files to CNC-machine.

• Visualizing G-code files.

mbpoll is a command line utility to communicate with ModBus slave (RTU or TCP).

GPX is a post processing utility for converting gcode output from 3D slicing software to x3g files for standalone 3D printing on common 3D printers.

The purpose of the MED module is to provide a standard for storing and recovering computer data associated to numerical meshes and fields, and to facilitate the exchange between codes and solvers.

The persistent data storage is based upon HDF format (like CGNS, a standard developed by Boeing and NASA in the area of Computational Fluid Dynamic).

MED also provides structures to hold data on meshes and fields. These structures are exchanged between solvers, hide the communication level (CORBA or MPI), and offer persistence (read/write in .med files).

The main benefit of a common exchange format is reduced complexity of code coupling. It also allows sharing such high level functionalities as computation of nodal connectivity of sub-elements (faces and edges), arithmetic operations on fields, entity location functionalities, and interpolation toolkit.

SOLVESPACE is a parametric 3D CAD tool. Applications include:

• modeling 3D parts — draw with extrudes, revolves, helixes and Boolean (union / difference / intersection) operations

• modeling 2D parts — draw the part as a single section, and export DXF, PDF, SVG; use 3D assembly to verify fit

• 3D-printed parts — export the STL or other triangle mesh expected by most 3D printers

• preparing CAM data — export 2D vector art for a waterjet machine or laser cutter; or generate STEP or STL, for import into third-party CAM software for machining

• mechanism design — use the constraint solver to simulate planar or spatial linkages, with pin, ball, or slide joints

• plane and solid geometry — replace hand-solved trigonometry and spreadsheets with a live dimensioned drawing

The system call intercepting library provides a low-level interface for hooking Linux system calls in user space. This is achieved by hot-patching the machine code of the standard C library in the memory of a process.

esptool.py is a Python-based utility to communicate with the ROM bootloader in Espressif ESP8266 & ESP32 series chips.

LibreCAD is a 2D Computer-aided design (CAD) application for creating plans and designs.

Libctl is a Guile-based library implementing flexible control files for scientific simulations.

libmodbus is a library to send/receive data with a device which respects the Modbus protocol. This library can use a serial port or an Ethernet connection.

Iaito is the official graphical interface for radare2, a libre reverse engineering framework. Iaito focuses on simplicity, parity with commands, features, and keybindings.

pcb2gcode is a command-line program for isolation routing and drilling of PCBs. It takes Gerber files as input and outputs G-code files for the milling of PCBs. It also includes an autoleveller for the automatic dynamic calibration of the milling depth.

LibSavitar is a C++ implementation of 3mf loading with SIP python bindings. It belongs to the Cura project from Ultimaker.

poke-elf is a GNU poke pickle for editing ELF object files, executables, shared libraries and core dumps. It supports many architectures and extensions.

Binary G-code is a new standard for encoding and compressing ASCII G-code files. G-code files are easy to read and interpret, but their downside is that the data is not saved efficiently, and the file size is often very large. Compression of the file is problematic because the printers usually run on limited hardware and they may not have enough memory and/or CPU power to decompress it.

Block and Binary G-Code is a new G-code file format featuring the following improvements over the legacy G-code:

• Block structure with distinct blocks for metadata vs. G-code.

• Faster navigation.

• Coding and compression for smaller file size.

• Checksum for data validity.

• Extensibility through new (custom) blocks. For example, a file signature block may be welcome by corporate customers.

The binary G-code format is flexible and the encoding and compression of individual blocks is variable. libbgcode library contains the routines to convert ASCII G-codes to binary and vice versa.

Harminv is a free program (and accompanying library) to solve the problem of harmonic inversion — given a discrete-time, finite-length signal that consists of a sum of finitely-many sinusoids (possibly exponentially decaying) in a given bandwidth, it determines the frequencies, decay constants, amplitudes, and phases of those sinusoids.

GNU LibreDWG is a C library to handle DWG files. It aims to be a free replacement for the OpenDWG libraries.

cutecom is a graphical serial terminal, like minicom. It is aimed mainly at hardware developers or other people who need a terminal to talk to their devices.

The OndselSolver library for assembly constraints and multibody dynamics is used by FreeCAD 1.0.0 for its new Assembly workbench.

Platypush is a general-purpose and extensible platform for automation across multiple services and devices with hundreds of supported integrations.

QElectroTech, or QET in short, is a desktop application to create diagrams and schematics. The software is primarily intended to create electrical documentation but it can also be used to draw any kinds of diagrams, such as those made in pneumatics, hydraulics, process industries, electronics, and others.