• CeCILL-CCECILL-CWeak copyleftCEA / CNRS / INRIA2013CEA / CNRS / INRIA — 2013 — The library-oriented weak-copyleft branch of the CeCILL family, roughly parallel to LGPL-style use cases.
• Common Development and Distribution License 1.0CDDL-1.0Weak copyleftSun Microsystems / Oracle2004Sun Microsystems / Oracle — 2004 — File-based weak copyleft license derived from MPL 1.1, used by projects such as OpenZFS and Illumos descendants.
• Common Development and Distribution License 1.1CDDL-1.1Weak copyleftSun Microsystems / Oracle2005Sun Microsystems / Oracle — 2005 — Updated CDDL revision retaining the same general file-level weak-copyleft structure.
• Eclipse Public License 1.0EPL-1.0Weak copyleftEclipse Foundation2004Eclipse Foundation — 2004 — The earlier Eclipse weak-copyleft license, historically important in Java tooling and enterprise software.
• Eclipse Public License 2.0EPL-2.0Weak copyleftEclipse Foundation2017Eclipse Foundation — 2017 — Weak copyleft used across the Eclipse ecosystem, designed around modularity and commercial compatibility.
• European Union Public License 1.2EUPL-1.2Weak copyleftEuropean Commission2017European Commission — 2017 — European public-sector weak copyleft license with explicit compatibility language for multiple other licenses.
• GNU Lesser General Public License v2.1LGPL-2.1-or-laterWeak copyleftFree Software Foundation1999Free Software Foundation — 1999 — The classic weak-copyleft library license of the pre-v3 GNU era, still common across infrastructure software.
• GNU Lesser General Public License v3.0LGPL-3.0-or-laterWeak copyleftFree Software Foundation2007Free Software Foundation — 2007 — Weak copyleft for libraries: the library itself stays free, but proprietary programs may link against it.
• GNU Lesser General Public License v3.0 onlyLGPL-3.0-onlyWeak copyleftFree Software Foundation2007Free Software Foundation — 2007 — LGPLv3 without the “or later” clause, preserving the exact GNU weak-copyleft text of version 3 only.
• GNU Library General Public License v2.0LGPL-2.0-or-laterWeak copyleftFree Software Foundation1991Free Software Foundation — 1991 — The older “Library GPL” predecessor to LGPL 2.1, historically significant in early free software libraries.
• Mozilla Public License 1.1MPL-1.1Weak copyleftMozilla Foundation1999Mozilla Foundation — 1999 — The older Mozilla file-level weak copyleft, historically important before the simplification and compatibility work of MPL 2.0.
• Mozilla Public License 2.0MPL-2.0Weak copyleftMozilla Foundation2012Mozilla Foundation — 2012 — File-level copyleft used by Firefox and Thunderbird — a middle ground between GPL and permissive licenses.