@fuxoft unfortunately it's not open source, it seems it uses a modified version of the Apache license but this one doesn't allow you to use the engine for profit purposes.
Even the GPL let you do that as long as you keep the code open.
@lorabe As I understand it, you CAN use the Defold engine to create commercial software. You CANNOT use the engine to create your own commercial game engine.
@fuxoft exactly, so technically this is not an open source software.