You'll see "open source" mentioned throughout this site, attached to programs like LibreOffice, GIMP and Blender, but the term gets thrown around without much explanation of what it actually means in practice, and why it tends to correlate with software that stays genuinely free rather than sliding towards a subscription over time.
Key takeaway: Open source means the program's underlying code is publicly available for anyone to inspect, modify and redistribute, which is why open-source software rarely disappears, changes owners unexpectedly, or starts charging without warning.
The basic idea
Every piece of software is built from source code — the human-readable instructions a programmer writes, which are then compiled into the program you actually run. With closed-source (proprietary) software, that source code is kept private by the company that owns it. With open-source software, the source code is published publicly, usually on a site like GitHub, under a licence that allows anyone to read it, copy it, modify it, and often redistribute their own modified version.
Why this matters practically, not just philosophically
- Transparency: Security researchers and other developers can inspect the code for hidden tracking, backdoors or bugs, rather than trusting a company's word alone.
- Longevity: If the original developer stops maintaining a project, the community can continue it, because the code isn't locked away. LibreOffice itself exists because of exactly this, having grown from an earlier open-source office suite.
- No surprise paywalls: Because anyone could take the code and maintain a free fork if a project suddenly started charging heavily, open-source projects have a natural pressure to stay genuinely free or reasonably priced.
- Free of cost, usually: Most open-source software is also free to download and use, though "open source" technically refers to the code being open, not the price — the two are related but not identical.
Open source doesn't automatically mean perfectly safe
Publicly available code means it can be reviewed, but that doesn't guarantee every open-source project actually gets reviewed carefully, or that vulnerabilities are found quickly. Popular, actively maintained projects with large communities (LibreOffice, GIMP, Blender, VLC) tend to benefit most from this scrutiny; a small, obscure open-source tool with one developer and little activity carries more of the same trust questions as closed-source software.
Tip: When choosing between similar tools, an active project (recent updates, an engaged community, responsive maintainers) is usually a better sign of ongoing reliability than "open source" as a label on its own.
Common licences you'll come across
Not all open-source licences work the same way. The GPL (GNU General Public License), used by LibreOffice and GIMP, requires that modified versions also stay open source if redistributed. More permissive licences like MIT or Apache allow modified versions to be closed off again. None of this usually affects you as an end user beyond understanding that "open source" covers a spectrum of specific legal terms, not one single set of rules.
Before you start: "Open source" and "free" are related but separate ideas. Always download open-source software from its official project page or a reputable app store, since the openness of the code doesn't stop a third-party site from bundling a modified installer with unwanted extras.
| Aspect | Open source | Proprietary (closed source) |
|---|---|---|
| Code visibility | Public | Private |
| Typical cost | Usually free | Often paid or subscription |
| Continuity if developer stops | Community can continue it | Usually discontinued |
Frequently asked questions
- Is open-source software always free of charge?
- Usually, but not by definition — a company can technically charge for open-source software, though the ability for others to freely redistribute the same code makes this uncommon in practice.
- Can I trust open-source software with sensitive personal data?
- Generally yes for well-established, actively maintained projects, since the code is open to independent scrutiny, though it's still sensible to check a project's reputation before installing anything unfamiliar.
- Do I need to understand programming to use open-source software?
- Not at all. The vast majority of open-source programs, like LibreOffice or GIMP, are designed for regular users with no coding knowledge required.