Licences

In short: A licence defines what someone may do with software, images, texts or fonts: use, change, share and under which conditions.

In more detail: Copyright lies with the author. Without a licence you may not use other people’s works. The licence permits it explicitly.

In Depth

Software

• Proprietary: the vendor keeps the rights, use usually only against purchase or subscription.
• Open source: the source code is open and may be used according to the licence rules.
  • Permissive (MIT, BSD, Apache 2.0): very free use, usually only with attribution.
  • Copyleft (GPL, AGPL): derived works must be under the same licence. LGPL is a middle path for libraries.

Content

• Creative Commons: building blocks such as BY (attribution), SA (share alike), NC (non-commercial), ND (no derivatives). CC0 frees everything.
• Fonts: e.g. the SIL Open Font License (OFL).

What to watch

Check the licences of libraries, images and fonts when you include them, ship the notices and mix compatible licences. This matters especially before selling or handing over a project. See also copyright and GDPR.

See also: open source, software