ReactOS will never be able to substitute for Windows, because it lags too far behind in development.
However, it could represent an opportunity to roll back the clock to Window's glory days, and become a second chance to do "Windows" right, for those who dislike the direction modern Windows developement has gone.
License:Comprehensible Open License 2.0
Comprehensible Open License 2.0:
Material provided under the terms of this license can be used, modified, duplicated, and distributed, provided the material remains free of charge, and the author of the material is not held responsible for any consequence of using it.
