Free and Open Source Software

posted by Rianne Schestowitz on Oct 11, 2026

• oasdiff - OpenAPI validation and breaking change detection

  A central feature is its breaking-change detection. oasdiff distinguishes between modifications that will break existing clients, changes that may cause compatibility problems and changes that are unlikely to affect consumers. Developers can use these findings to prevent accidental API regressions.

  oasdiff also provides a standalone validation command that checks specifications for invalid types, missing required fields, unresolved references and other violations. The application runs locally and can be integrated into continuous integration workflows, including GitHub Actions.

  This is free and open source software.

• QRrs - generate and read QR codes

  Generated QR codes can be saved as image files or displayed directly in the console using block characters. QRrs can also decode QR codes from image files and print the embedded text, making it useful both for interactive use and automated workflows.

  Input can be supplied directly as an argument or piped to QRrs through standard input. This makes the program easy to integrate with shell scripts and other command-line utilities. Output filenames can be specified explicitly, while options are available for adjusting the QR code margin and inverting foreground and background colors.

  QRrs also supports configurable error correction levels and can read QR codes stored in SVG files. Its small scope and simple syntax make it particularly suitable for users who want QR code generation and decoding without a graphical application or web service.

  This is free and open source software.

• doh - DNS-over-HTTPS command-line client

  Results are streamed to standard output as newline-delimited JSON objects. This makes doh particularly convenient for scripting and for use with utilities such as jq. Instead of presenting a heavily formatted interactive display, the program produces structured data that can be filtered, transformed or redirected to a file.

  The client provides control over timeouts and the maximum number of retries made for each query. It also lets you specify the resolver used to look up the hostname of the DoH server itself, together with the network protocol used for that bootstrap lookup.

  There is also an option to permit connections to DoH servers using certificates that cannot be verified, although that option naturally reduces the protection normally provided by HTTPS.

  doh is a focused tool. It is especially useful when testing DoH endpoints, comparing resolver responses or incorporating encrypted DNS lookups into command-line workflows.

  This is free and open source software.

• Decloaker - reveal objects hidden by malware

  The software obtains information through several independent mechanisms so that discrepancies can be identified. Its file commands can list, read, copy, move, remove and inspect files without relying on libc, helping expose objects concealed by LD_PRELOAD-based rootkits that intercept ordinary library calls.

  For supported filesystems, Decloaker can also inspect data directly through the underlying disk device. Dedicated scanning commands look for hidden files, hidden file content, hidden processes, suspicious processes, hidden sockets and hidden kernel modules. A broader system scan combines several of these checks to provide a more comprehensive view of possible concealment.

  Network facilities can obtain connection information through netlink and inspect the kernel connection tracking table. Decloaker can also dump running tasks, open files and loaded kernel modules directly from kernel information rather than depending entirely on interfaces such as /proc. Comparing these independent sources can help expose inconsistencies created by malware attempting to hide its activity.

  This is free and open source software.

• Gosling.js - declarative genomic data visualisation

  The application is designed for situations where conventional genome browsers are too restrictive. Researchers may want to create unusual combinations of tracks, experiment with different graphical representations or build interactive views tailored to particular datasets.

  Gosling.js uses rendering and data-access capabilities from HiGlass, allowing visualisations to handle large genomic datasets. Its approach makes it possible to describe complex displays without implementing every graphical component and interaction from scratch.

  This is free and open source software.

• PixelPen - pixel art editor and animation tool

  PixelPen is a pixel art editor and animation tool built with the Godot Engine. It can run as a standalone application on Linux or as an add-on inside the Godot editor. That makes it suitable both for general pixel artwork and for artists creating assets directly alongside a Godot project.

  Projects combine the canvas, palette, layers and animation data rather than treating the artwork as a single flattened image. PixelPen uses its own project format to preserve this structure, while export functions provide conventional image and animation output when the work is ready to use elsewhere.

  This is free and open source software.

• Curium - privacy-first QR code generator and scanner

  The generator supports URLs, text, Wi-Fi credentials, email, phone numbers, SMS, contacts, locations, calendar events and OTP authentication. QR codes can be extensively customized with numerous pixel, eye and pupil styles, colors, logos, borders and shadows.

  Curium can scan QR codes and several barcode formats, including EAN-13, Code 128, PDF417, Aztec and Data Matrix. Existing QR codes can be scanned, restyled and exported. Batch generation, reusable templates, local history, PNG and SVG export, CSV import/export and multiple interface themes are also provided.

  This is free and open source software.

• LinuxLinks Is Changing – A Fresh Look and Updated Content

  We’ve been making a few changes to LinuxLinks recently. If you’re a regular visitor, you may have noticed the cleaner header, changes to the spacing and a few adjustments to the article layout. We have made significant improvements to the speed of the site. And we’ve also been spending a lot of time going back through our software coverage.

  We thought it was worth explaining what we’re doing and asking how you’re finding it.

• Open Photo AI - AI-powered photo enhancement application

  The software can remove sensor noise and rain, restore damaged or low-quality faces, colorize black-and-white photographs, correct exposure and color balance, sharpen blurred images and upscale low-resolution material. Several models are available for many of these tasks, allowing users to choose between processing speed, fidelity and restoration strength.

  An Autopilot mode can analyse loaded images and suggest appropriate enhancements automatically. Alternatively, users can manually build their own processing workflow and apply multiple enhancements before exporting the resulting images.

  Open Photo AI uses open source machine learning models and supports hardware-accelerated inference. Its processing engine uses ONNX Runtime with support for acceleration technologies including CUDA, TensorRT and WebGPU where suitable hardware is available.

  This is free and open source software.