When Oracle acquired Sun Microsystems, Hudson's community voted 93% to fork and rebrand as Jenkins.
When AWS launched a managed Elasticsearch service without collaborating, Elastic changed their license — triggering a years-long feud that only resolved in 2024 with triple licensing.
Oracle still holds the "JavaScript" trademark, and Deno Land is fighting to cancel it.
These aren't hypotheticals — they're consequences of licensing decisions that every developer should understand but few do.
This lightning talk walks through the families of open-source licenses — permissive (MIT, Apache 2.0, BSD), copyleft (GPL v2/v3, AGPL), and the newer source-available models (SSPL, BUSL) — using real corporate battles as case studies. We'll cover why GPL v2's SaaS loophole led to AGPL, why MongoDB's SSPL was rejected by OSI, and what happens when one AGPL component can infect your entire stack.
Most developers write 4 lines of code but pull in 12 dependencies — each carrying its own license. One wrong dependency in a commercial product can mean forced open-sourcing of your codebase, legal notices, or worse. Licensing isn't a legal team problem anymore — it's a developer problem, and every npm install, pip install, or mvn dependency deserves a second look.
