Open-source licenses
One page per license: obligations in plain English, the commercial-use answer, and a directory of its pairwise compatibility verdicts. General guidance, not legal advice.
MIT permissive Do anything; keep the copyright notice and license text. BSD-2-Clause permissive Permissive; retain notice and disclaimer. BSD-3-Clause permissive Permissive; retain notice plus the no-endorsement clause. ISC permissive Functionally equivalent to MIT/BSD-2. Apache-2.0 permissive Permissive WITH an express patent grant. BSL-1.0 permissive Permissive; no notice required for binary-only distribution. Unlicense public domain Public-domain dedication. CC0-1.0 public domain Public-domain dedication. MPL-2.0 weak copyleft File-level copyleft. EPL-2.0 weak copyleft Module-level copyleft. LGPL-2.1 weak copyleft Library copyleft. LGPL-3.0 weak copyleft Like LGPL-2.1 with GPLv3-era patent and anti-tivoization terms. GPL-2.0-only strong copyleft Strong copyleft. GPL-2.0-or-later strong copyleft Same as GPL-2.0 but the 'or later' clause permits upgrading to GPLv3, which restores compatibility with GPLv3 and Apache-2.0 code (via the v3 path). GPL-3.0-only strong copyleft Strong copyleft with patent and anti-tivoization terms. AGPL-3.0 network copyleft GPLv3 PLUS a network clause: making the software available over a network (SaaS) counts as distribution, so you must offer source to remote users.