Copyleft: The Cheeky Hero of Open-Source Software!

Hey there, fellow tech enthusiasts and software wizards! Today, we're diving into the fascinating world of copyleft – the rebellious sibling of copyright that's all about sharing, freedom, and a splash of humor!

Back in the groovy year of 1976, developer extraordinaire Dr. Li-Chen Wang decided to shake things up and created the word "copyleft" in a sassy showdown with the all-too-serious term "copyright." He crafted a distribution notice for his Palo Alto Tiny BASIC programming language that read, "COPYLEFT ALL WRONGS RESERVED." You see, Dr. Wang wanted to have a little fun and poke at none other than Bill Gates himself, who was feeling a bit miffed about software hobbyists pirating the Altair BASIC program.

Now, to be clear, that witty line didn't have any legal muscle behind it, but boy was it catchy! It marked the birth of copyleft, the champion of the "free software" world, valiantly battling against the forces of proprietary and copyrighted software.

Enter Richard Stallman, the fearless advocate of free software, who embraced the word "copyleft" like a true hero and turned it into the foundation of the mighty GNU Project during the glorious 1980s.

So, what's copyleft all about, you ask? It's a daring method that lets you reuse and modify intellectual property without any pesky restrictions. The only caveat is that any fantastic new creations spun from the original asset must also be set free to roam the wild plains of openness. From works of art to software marvels, copyleft's got you covered!

But hey, not all copyleft licenses are created equal! There's a fierce battle between the "Strong vs. Weak Copyleft." Imagine it like a sword fight in the tech realm! The GNU GPL license, a formidable force, applies its copyleft magic to all derived works and software components in the package. On the other hand, the GNU Lesser GPL, the cunning trickster, sneaks its copyleft prowess only into the original copylefted work.

License	Copyleft Strength	Can Link with Proprietary Software?	Notes
GNU General Public License (GPL) v2	Strong Copyleft	❌ No	Entire derivative work must be GPL.
GNU General Public License (GPL) v3	Strong Copyleft	❌ No	Adds patent protection, anti-Tivoization (hardware lockouts).
GNU Affero General Public License (AGPL) v3	Strong Copyleft (Network Copyleft)	❌ No	Also applies if users interact over a network (e.g., web services).
GNU Lesser General Public License (LGPL) v2.1	Weak Copyleft	✅ Yes, with conditions	Designed for libraries; linking allowed under terms.
GNU Lesser General Public License (LGPL) v3	Weak Copyleft	✅ Yes, with conditions	Stronger protection against tivoization and patents compared to v2.1.
Mozilla Public License (MPL) 2.0	Weak Copyleft	✅ Yes	File-level copyleft: only MPL-covered files must remain open.
Mozilla Public License (MPL) 1.1	Weak Copyleft	✅ Yes	Older version, compatible with some proprietary linking.
Eclipse Public License (EPL) 1.0	Weak Copyleft	✅ Yes	Modification of EPL components must remain EPL; can be combined otherwise.
Eclipse Public License (EPL) 2.0	Weak Copyleft	✅ Yes	Updated version, better GPL compatibility.
Common Development and Distribution License (CDDL) 1.0	Weak Copyleft	✅ Yes	File-based copyleft; CDDL-licensed files stay open, rest can be closed-source.
Sleepycat License	Strong Copyleft (for databases)	❌ No	Copyleft for Berkeley DB database usage; derivatives must be open.
Open Software License (OSL) 3.0	Strong Copyleft	❌ No	Strict, including network use; broader patent clause.
Apple Public Source License (APSL) 2.0	Weak Copyleft	✅ Yes	Copyleft applies only if you deploy the software externally.
RealNetworks Public Source License (RPSL)	Strong Copyleft	❌ No	Similar to GPL, accepted by OSI but not FSF.
Sun Public License (SPL)	Weak Copyleft	✅ Yes	Predecessor to CDDL; limited copyleft.
European Union Public License (EUPL) 1.2	Strong Copyleft (but interoperable)	❌ No (with minor exceptions)	Strong copyleft within Europe, but explicitly allows compatibility with GPL and others.
Q Public License (QPL)	Strong Copyleft	❌ No	Requires changes to be open; designed for Qt toolkit originally.
Watcom Public License	Strong Copyleft	❌ No	Rare license, strong copyleft, very permissive distribution requirements.

Now, let's talk about the epic showdown: Copyleft vs. Copyright!

It's like the ultimate clash of ideologies. Copyright holds all the power, giving the work's owner full control over reproduction, modification, and use of their precious creation. But wait! Here comes copyleft, swooping in like a superhero, using the very law of copyright to enforce freedom of use and grant the gift of software modification, distribution, and unlimited use to the community. Take that, restrictive copyright!

So, in conclusion, while copyright might feel like a tight straitjacket, copyleft is like a sparkly cape that sets freedom loose on all subsequent material based on the original work. It's like magic, but better!

And there you have it, folks – the tale of copyleft, the hero of open-source development, bringing joy and giggles to the hearts of software lovers everywhere. Now, go forth and spread the word of copyleft like a tech-savvy bard, singing its praises to the four corners of the digital realm!

Oh, and before we part ways, here are some of the popular copyleft licenses you might encounter on your adventurous coding journey:

• Eclipse Public License 1.0 (EPL-1.0)

• GNU Affero General Public License v3 (AGPL-3.0)

• GNU General Public License v2.0 (GPL-2.0)

• GNU General Public License v3 (GPL-3)

• GNU Lesser General Public License (LGPL)

• GNU Lesser General Public License v3 (LGPL-3.0)

• Microsoft Reciprocal License (Ms-RL)

• Mozilla Public License 2.0 (MPL-2.0)

  
  

Go forth and conquer the world of copyleft, my friends! Happy coding and may the humor be with you!