Open-source software is software whose source code anyone can read, change and share under a licence such as the GPL, MIT or Apache licence. Much of it is also free to use, and it runs a large part of the web, including the servers behind most websites. This guide lists well-maintained open-source tools by category, as of 2026, and flags popular tools that are no longer open source or no longer maintained.
For most needs there is a mature open-source option: Linux (Ubuntu, Debian, AlmaLinux) for servers, Firefox for browsing, LibreOffice for documents, GIMP, Inkscape and Blender for design, and Git, PostgreSQL and nginx for development. Check the licence before you rely on a tool: Terraform, Vagrant and MongoDB are now "source-available" rather than open source, and Atom and CentOS Linux have ended.
1. Open source, free and source-available: know the difference
- Open source means an OSI-approved licence: you may use, study, change and redistribute the code.
- Free of charge is not the same thing. Some open-source products sell hosted or support plans, and some free downloads are not open source at all.
- Source-available means you can read the code, but the licence restricts use, often competing hosted services. Several well-known tools moved to such licences in recent years.
A tool that was open source when you adopted it can change licence in a later version. Before you build a business on one, read the current licence on the project's own site, and note any community fork that kept the open licence.
2. Operating systems and desktop basics
| Software | Use it for | Note |
|---|---|---|
| Ubuntu (LTS releases) | Desktops and servers | Choose a long-term support release for servers |
| Debian | Stable servers and desktops | The base Ubuntu is built on |
| Fedora | Up-to-date desktop for developers | Short release cycle |
| AlmaLinux and Rocky Linux | Enterprise Linux servers | Replacements for CentOS Linux, which has ended |
| Arch Linux | Minimal, hands-on setups | For experienced users |
| FreeBSD | Servers and network appliances | Unix-like, not Linux |
Browsers: Firefox, Chromium (the open-source base of Chrome), Brave, and Tor Browser for anonymous browsing. Email client: Thunderbird.
3. Office, design and media
| Software | Use it for | Replaces |
|---|---|---|
| LibreOffice | Documents, spreadsheets, presentations | Microsoft Office |
| ONLYOFFICE | Office documents with strong .docx/.xlsx compatibility | Microsoft Office |
| GIMP | Photo editing | Photoshop |
| Inkscape | Vector graphics and logos | Illustrator |
| Krita | Digital painting | Painting apps |
| Blender | 3D modelling, animation, video editing | 3D suites |
| darktable | RAW photo workflow | Lightroom |
| Audacity and Ardour | Audio editing and recording | Audio editors and DAWs |
| Kdenlive, Shotcut, OpenShot | Video editing | Consumer video editors |
| OBS Studio | Screen recording and live streaming | Streaming software |
Apache OpenOffice still exists but sees very little development; LibreOffice is the actively maintained choice.
4. Code editors and developer tools
| Software | Use it for | Note |
|---|---|---|
| VSCodium | Code editing with VS Code's features | Open-source build of VS Code; Microsoft's own VS Code download uses a proprietary licence |
| Vim and Neovim | Terminal-based editing | Available on almost every server |
| Zed | Fast modern code editor | Open source since 2024 |
| Eclipse IDE and Apache NetBeans | Java and multi-language IDEs | Long-running projects |
| Git | Version control | The standard for source code |
| Docker Engine and Podman | Containers | Docker Desktop has separate commercial terms |
| Kubernetes | Running containers at scale | Complex; for multi-server setups |
| Ansible | Server automation | Agentless, uses SSH |
| OpenTofu | Infrastructure as code | Open-source fork of Terraform |
Removed from older lists: Atom (archived by GitHub in 2022), Sublime Text (proprietary, never open source), Terraform and Vagrant (moved to a source-available licence in 2023).
5. Databases and web servers
| Software | Type | Note |
|---|---|---|
| PostgreSQL | Relational database | Feature-rich and standards-compliant |
| MySQL Community and MariaDB | Relational database | The usual choice for PHP sites and WordPress |
| SQLite | Embedded database | A single file, no server needed |
| Valkey | In-memory key-value store | Open-source fork of Redis |
| Apache HTTP Server | Web server | Supports .htaccess |
| nginx | Web server and reverse proxy | Efficient under heavy load |
| Caddy | Web server | Automatic HTTPS |
| HAProxy | Load balancer and proxy | TCP and HTTP |
MongoDB is widely used, but its server licence (SSPL) is not OSI-approved, so it counts as source-available.
6. Websites, files and collaboration
| Software | Use it for |
|---|---|
| WordPress | Websites, blogs and, with WooCommerce, online shops |
| Joomla and Drupal | Structured sites and portals |
| Ghost | Publishing and newsletters (Node.js) |
| Moodle | Online courses and learning management |
| Nextcloud | Self-hosted file sync, calendar and contacts |
| Syncthing | Direct device-to-device file sync |
| Mattermost, Rocket.Chat, Zulip | Team chat |
| Matrix with Element | Decentralised, encrypted messaging |
| OpenProject, Redmine, Taiga, Kanboard | Project management and issue tracking |
7. Security, monitoring, virtualisation and backup
| Software | Category | Use it for |
|---|---|---|
| KeePassXC | Security | Offline password manager |
| VeraCrypt | Security | Disk and container encryption |
| WireGuard and OpenVPN | Security | VPNs |
| Signal | Security | End-to-end encrypted messaging |
| Prometheus with Grafana | Monitoring | Metrics, dashboards and alerts |
| Zabbix and Nagios Core | Monitoring | Infrastructure monitoring |
| htop and btop | Monitoring | Live process view in the terminal |
| Proxmox VE | Virtualisation | Running VMs and containers on your own hardware |
| QEMU/KVM | Virtualisation | Linux's built-in hypervisor |
| VirtualBox | Virtualisation | Desktop VMs; the Extension Pack has a separate licence |
| rsync, restic, BorgBackup | Backup | File sync and encrypted, de-duplicated backups |
| Duplicati and Clonezilla | Backup | Scheduled backups and disk images |
Game development: Godot Engine for 2D and 3D games. Education: GCompris for young children.
8. How to choose well
9. Running open-source software on Domain India
Much of this list is what hosting runs on. Our shared hosting is Linux with the Apache web server, and the servers run CloudLinux.
- Shared hosting (cPanel, DirectAdmin): install WordPress, Joomla, Drupal, PrestaShop and many more with Softaculous. MySQL databases, Git Version Control on cPanel, and Node.js and Python apps through the panel's app tools are available. Jailed SSH is available on every shared plan on request; it is off by default. MongoDB and Redis are not available on shared hosting.
- App Platform: Node.js apps are detected automatically; anything else, such as Ghost or a Python service, deploys from a Dockerfile. See Getting started with the App Platform.
- VPS: self-managed, with root access. Run Nextcloud, Mattermost, Docker or your own database server. See VPS plans.
For which versions run on our shared servers, see the hosting compatible technologies list.
Is open-source software always free?
Usually free to download and use, but not always free of cost. Some projects sell hosted versions or support. Open source refers to the licence, which lets you use, change and share the code.
What is the difference between open source and source-available?
Open-source licences are OSI-approved and allow any use, change and redistribution. Source-available licences let you read the code but restrict some uses, such as offering the software as a competing hosted service.
Is Visual Studio Code open source?
The VS Code source code is MIT-licensed, but Microsoft's official download is released under a proprietary licence and includes telemetry. VSCodium is a fully open-source build of the same code.
What replaced CentOS Linux for servers?
CentOS Linux has ended. AlmaLinux and Rocky Linux are the main community replacements that stay compatible with Red Hat Enterprise Linux. Debian and Ubuntu LTS are also common server choices.
Is Terraform still open source?
No. Terraform moved to a source-available licence in 2023. OpenTofu is the open-source fork maintained under the Linux Foundation.
Can I install open-source apps on Domain India shared hosting?
Yes. On cPanel and DirectAdmin shared hosting, Softaculous installs WordPress, Joomla, Drupal, PrestaShop and many others. Tools that need Docker or root access need a VPS or the App Platform.
Ready to run open-source software online? Start a site on cPanel hosting with one-click installs, deploy an app on the App Platform, or take full control with a VPS.
Linux hosting with Softaculous one-click installs, free SSL and weekly JetBackup backups on cPanel and DirectAdmin.
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