May 6, 2026
Open source, open wallet
How I made $350K from an open-source JavaScript library using dual licensing
He turned a free coding tool into $350K, and the comments instantly called it a sales pitch
TLDR: A developer says a free-but-not-really-free licensing strategy helped his JavaScript tool make $350K from companies that wanted to keep their code secret. Commenters split fast: some called it smart creator payback, while others said the post felt more like a stealth ad than a victory lap.
A developer says he made more than $350,000 from a tiny JavaScript photo gallery tool by using a simple-sounding trick: give it away under strict open-source rules, then charge companies that want to keep their own code private. In plain English, the pitch is: hobbyists can use it for free, but businesses that don’t want to reveal their entire website can pay up. That alone was enough to get the comment section buzzing, but the real fireworks started when readers hit the line revealing he’s a co-founder of Kelviq, the payment and license tool mentioned in the post.
That disclosure turned the thread from “interesting business model” into “wait… is this just an ad?” One of the loudest reactions flat-out said the confession should have been at the top, not buried near the end. Others questioned whether the $350K really came from the library itself, hinting it may have been bundled with other products. Then came the classic open-source civil war: some readers praised the idea as overdue payback for creators whose work quietly fuels giant companies, with one saying this is exactly what Tailwind should have done. But skeptics piled on with warnings that even these strict licenses don’t always stop big cloud companies from finding a workaround.
The funniest part? Amid all the monetization drama and legal talk, one refreshingly honest commenter cut through the chaos with: “What’s dual licensing i’m kinda interested.” Honestly, same.
Key Points
- •The article says the creator of lightGallery earned more than $350,000 in four years using a dual-licensing model.
- •Dual licensing is described as offering software under a free copyleft license such as GPL or AGPLv3 and a paid commercial license for proprietary use.
- •The article distinguishes GPLv3 and AGPLv3 by their compliance triggers: distribution for GPLv3 and network interaction for AGPLv3.
- •For dual licensing to work with outside contributions, the article says maintainers need rights to re-license code, typically through a CLA or CAA.
- •The article says Kelviq is used for license fulfillment, checkout, tax handling, and compliance, and discloses that the author is a co-founder of Kelviq.