Comparative Open Source Licensing an Introduction

Introduction Comparative Open Source Licensing An Introduction

Alison Lloyd

IANAL Speech vs. Beer

• This represents my interpretation only • This does NOT constitute legal advice • Free software, as in freedom to do what • For proper legal advice, talk to a lawyer you like with it – ‘free speech’ - Libre • Free software, as in software that costs nothing – ‘free beer’ - Gratis • Free, open source, FOSS, F/OSS, FLOSS

Categorisation License usage

• Self propagating vs. non-propagating • Google figures (Chris DiBona) – Strong / weak copyleft – 48% GPL • Linking (possibly with non-FOSS code) – 23% LGPL • Redistribution – 14% BSD • Changes to licensed code – 6% Apache – 5% MIT • Internal usage – 5% Everything else

1 Where do FOSS licenses come License usage from? • Black Duck Software • Free Software Foundation (FSF) – 52% GPL (v2 and v3) • Open Source Initiative (OSI) – 9% LGPL (v2 and v3) • ‘Legacy’ – 8% Artistic license (Perl) • Anyone who rolls their own – 8% MIT – 6% BSD – 5% Apache – 12% Everything else

GNU Public License Lesser GPL • Must pass on source to downstream users • As for GPL, but: • …including any modifications you’ve made, noting your modifications – Allows linking with non-GPL code • Any software incorporating GPL code must be – Non-viral released under GPL • Still need to make source available to – Compatible licenses downstream users • May not impose further restrictions • v2 vs. v3 • Still need to release (under LGPL or GPL) • Static vs. Dynamic linking any changes to LGPL code • Affero GPL (AGPL)

BSD MIT

• No obligation to redistribute source or changes • As BSD • May not use licensor name to promote • Some variance: X11, Expat, ncurses your product • Originally written for X11 system • May be combined into proprietary products • Possibly less ambiguous than BSD, so • Original (4-clause), Modified (3-clause), some people prefer it over BSD Simplified (2-clause) • Permissive

2 Apache LaTeX (LPPL)

• Permissive • Similar to MIT/BSD… • …as per BSD/MIT licenses • …but strict controls on what goes into • Must preserve copyright / license notices licensed product • Must make changes explicit • Controls over name and maintainer • NOTICE file • Based on TeX license (Donald Knuth) • Currently v2.0 • LPPL itself is copyright

Public Domain Others

• Essentially anything not covered by any • WTFPL – ‘Do What The F*ck You Want intellectual property rights at all Public License’ • ‘intangible to private ownership’ • Creative Commons • Software must be explicitly placed into • Mozilla public domain • EPL • FOSS != Public Domain • etc.

Choosing a license Patents

• Software patents pose a serious threat to • Try to choose one of the existing ones FOSS software rather than making up a new one • Some licenses attempt to address this • How do you want people to use your (GPL, Apache) code? (and do you even care?) • Anecdotal evidence that software • Political considerations engineers not in favour of software patents – Employers wishes – Personal support for FOSS ideals

3 Useful information

• My email: [email protected] • GPL: http://www.gnu.org/licenses/gpl.html • LGPL: http://www.gnu.org/licenses/lgpl.html Questions / pig wrestling? • BSD: http://www.opensource.org/licenses/bsd-license.php • MIT: http://www.opensource.org/licenses/mit-license.php • Apache: http://www.apache.org/licenses/LICENSE-2.0 • LaTeX: http://www.latex-project.org/lppl/

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