Best Free and Open Source Software

posted by Rianne Schestowitz on Sep 19, 2026

• OpenXPKI – enterprise-grade PKI management platform

  OpenXPKI can manage multiple separate certificate authorities from a single installation and supports automated rollover between CA generations. It offers SCEP and EST enrollment and can interact with external certificate authorities, including services using ACME.

  Cryptographic operations can be delegated to supported hardware security modules, allowing private CA keys to be protected by dedicated hardware. The platform also offers extensive automation facilities for organisations managing large numbers of certificates.

  OpenXPKI is built around Perl and OpenSSL and is designed for Unix-like systems. Its combination of workflows, multiple CA support and lifecycle management makes it particularly suited to more complex internal PKI deployments.

  This is free and open source software.

• agevault – directory encryption using age

  agevault is a small command-line utility for treating a directory as an encrypted vault using age.

  Its workflow deliberately stays narrow: generate a passphrase-protected identity, lock a directory, and unlock it again when access is required. When locking a vault, agevault archives the directory and encrypts that archive to the public recipient embedded in the identity filename. Unlocking requires the passphrase needed to decrypt the corresponding private identity. This means possession of either the identity file or passphrase alone is insufficient. The project intentionally exposes no general configuration system, keeping the workflow close to age’s simplicity. Upstream explicitly states that agevault has been tested but has not undergone a formal security audit.

  This is free and open source software.

• IPED - digital evidence processor and analysis tool

  IPED (Digital Evidence Processor and Indexer) is a Java-based digital forensics platform for processing and analysing large collections of digital evidence.

  It combines command-line case processing with an integrated analysis interface, allowing investigators to ingest evidence, create searchable indexes and examine files, metadata and relationships within a case. The software was originally developed by digital forensic specialists from the Brazilian Federal Police and remains focused on efficient processing and handling substantial evidence sets.

  IPED supports Linux and Windows and can create portable cases that can subsequently be examined without installing the full processing environment.

  This is free and open source software.

• SBOM Tool - scalable Software Bill of Materials generator

  SBOM Tool is a command-line utility for creating Software Bills of Materials from software build artifacts.

  It is intended for scalable use in development and release pipelines, where an inventory of files, components and dependencies needs to accompany shipped software. The program scans both the material being distributed and the source or build-component directories used to produce it. Component discovery is delegated to Microsoft’s Component Detection libraries, while ClearlyDefined can supply additional licensing information. The resulting manifest can then be retained with an artifact or passed to other compliance and security processes.

  This is free and open source software.

• Pawn Appétit - modern chess analysis and training application

  The application supports UCI chess engines, allowing users to install and manage different engines for position and game analysis. Stockfish can be used for immediate analysis, while other compatible engines can be added according to preference. Games can be opened from PGN files or imported from online chess services including Lichess and Chess.com. This makes the program suitable both for analysing individual games and for maintaining a larger personal collection.

  Pawn Appétit includes facilities for building and practising opening repertoires. Repertoire material can be trained using spaced repetition, which schedules positions according to previous performance rather than presenting every line equally often. The application also provides exact and partial position searches across stored games, helping users locate positions that share particular piece arrangements or structures.

  The GUI includes dedicated areas for playing games, analysing positions, solving puzzles and studying material. Appearance settings and keyboard shortcuts can be customised, and engine and database management are handled from within the application rather than requiring separate utilities.

  This is free and open source software.

• SD – dynamic directory navigation utility

  SD is a command-line directory navigation utility for ksh, Bash and Zsh.

  It behaves like cd when given a valid pathname, while adding pattern-based navigation through a dynamically ranked directory stack. Unlike many directory jumpers that store only an aggregate score for each location, SD retains an explicit history of directory-change events. Rankings can therefore be recalculated when scoring parameters change without discarding that history. Its scoring model combines frequency and recency over a configurable trailing window, and repeated searches using the same pattern cycle predictably through matching directories in rank order. The repository is maintained as a read-only snapshot of stable project states.

  This is free and open source software.

• transcrypt – transparent encryption for Git repositories

  transcrypt is a Bash utility that configures transparent encryption for selected files inside a Git repository.

  It uses Git clean and smudge filters so protected files are encrypted when committed and decrypted again in an authorised working copy. Other contributors can still work with unencrypted parts of the repository without knowing the encryption password, which makes it useful for selectively protecting credentials, keys and configuration data rather than encrypting an entire repository. The tool relies on OpenSSL for its symmetric cryptography instead of implementing its own cipher primitives. Upstream also documents an important limitation: its default CBC-based encryption does not provide authenticated encryption, so malicious ciphertext modification is possible in some circumstances.

  This is free and open source software.

• step-ca – online certificate authority for automated certificate management

  The software can issue X.509 certificates for servers, clients, APIs, containers, virtual machines, databases and other infrastructure. It can also operate as an SSH certificate authority, issuing certificates for users and hosts instead of relying entirely on conventional SSH public keys.

  Automation is a major focus. step-ca includes an ACME server supporting common ACME challenge types and can authorize certificate requests using mechanisms including OpenID Connect identity tokens, cloud instance identity documents, JWK tokens, SCEP and existing X.509 certificates.

  The software can operate as an online intermediate beneath an existing root certificate authority. It supports multiple key types and configurable certificate lifetimes, including short-lived certificates intended to reduce reliance on conventional revocation mechanisms.

  This is free and open source software.

• Nexterm – self-hosted server management platform

  It is designed to replace a collection of separate tools with one central workspace for working with machines, files, scripts and virtualised or containerised workloads. Resources can be arranged into folders and tabs, while organisation support helps teams keep users and infrastructure logically separated. Nexterm also includes a remote browser which runs from the server-side network: pages and internal hostnames are reached through an SSH server, making it possible to open interfaces for routers, firewalls, NAS devices and other systems that are not directly reachable from the administrator’s local network.

  This is free and open source software.

• 13 Best Free and Open Source Linux Raster Image Editors

  These applications are useful for photographers, designers, illustrators, web developers and anyone who needs to manipulate digital images. Typical tasks include correcting exposure or colour, removing unwanted objects, preparing graphics for websites and social media, combining several images into a composition, restoring photographs, creating banners and other artwork, or simply cropping and resizing an image. Some raster editors are lightweight applications aimed at straightforward everyday editing, while others provide sophisticated toolsets suitable for professional creative work.

  We exclude software primarily designed for RAW development, batch processing, digital painting, pixel art and vector graphics, as these are covered in separate roundups.

  Here’s our verdict captured in a legendary LinuxLinks-style ratings chart. Only free and open source software is eligible for inclusion here.

• Best Free and Open Source Scala Linter Tools

  A linter is a tool used in software development to analyze source code for potential errors, stylistic issues, and adherence to coding standards. It essentially acts as a static code analyzer, examining the code without actually executing it. Linters help developers catch issues early in the development cycle, improving code quality and maintainability

  Linters are useful tools for maintaining code quality and consistency in your Perl applications. They analyze code for potential issues, enforce coding standards, and help catch errors before they are pushed into production. Linters are not necessarily a quick fix, can be a distraction, and it’s not inconceivable that they may not be helpful with old, large code bases.

  This article picks some useful tools to help you fix Scala code.

  Here’s our verdict captured in a legendary LinuxLinks-style ratings chart. Only free and open source software is eligible for inclusion here.

• Zsh-z - fast directory navigation for Zsh

  It learns from the directories you visit and uses “frecency” — a combination of frequency and recency — to predict where you want to go from a short search string. Instead of repeatedly typing long paths, you can enter a fragment such as z src and let Zsh-z choose the highest-ranked matching location. The project is a native Zsh port of rupa/z, replacing its mixture of shell code and external utilities with a pure Zsh implementation. It can use the same database as z, which makes migration straightforward and allows the two tools to coexist when different shells are used.

  This is free and open source software.

• 2FAS Auth – private two-factor authenticator for Android

  The interface offers tools for managing larger token collections, including search and token customization with groups, icons, badges and labels. Access to the application can be protected with a PIN, while tokens can be hidden until they are needed.

  2FAS Auth also integrates with the project’s optional browser extension. After pairing a browser with the mobile application, a login request can be confirmed on the phone and the required token passed to the browser over an end-to-end encrypted connection. This avoids manually finding and typing six-digit codes while leaving the user in control of the authorization.

  This is free and open source software.

• Aegis Authenticator – secure 2FA app for Android

  The software gives users considerable control over their authentication data. Entries can be imported from a wide range of other authenticator apps, including Google Authenticator, Microsoft Authenticator, Authy, FreeOTP, andOTP and 2FAS Authenticator, although some import methods require root access. Users can also export their vault in plaintext or encrypted form.

  Aegis provides automatic backups to a user-selected location, making it easier to recover authentication tokens after replacing or losing a device. Entries can be grouped, searched and sorted, while custom and automatically generated icons make larger collections easier to navigate. Its interface supports several themes and viewing styles.

  This is free and open source software.