Defold, originally developed by King (of Candy Crush fame), is making waves in the game development community with its distinctive source-available licensing model. Unlike traditional open-source engines, Defold offers developers unprecedented flexibility while maintaining clear boundaries for commercial use.

The engine's approach centers on a modified Apache license that allows developers to modify the source code without mandatory public disclosure. This means game creators can build proprietary extensions and games without being required to open-source their specific implementations—a significant departure from more restrictive licensing models.

Online commentators have praised Defold's strategy, seeing it as a potential solution to challenges faced by other game engines. The licensing allows developers to monetize games freely while preventing third parties from commercially exploiting the engine itself. This balance is particularly appealing in an industry where platform control can make or break a development tool.

Technically, Defold distinguishes itself with strong cross-platform support and a focus on 2D and mobile game development. Its use of Lua as a scripting language, while initially controversial, has found defenders who argue it provides a pragmatic and performant development experience.

The engine's journey from an internal King project to an independent foundation reflects a broader trend of technology companies spinning out promising tools. By maintaining a community-focused approach while protecting their intellectual property, the Defold team appears to be walking a nuanced line between openness and sustainability.