Original: In April 2000, MINIX became free/open source software under a permissive free software licence, but by this time other operating systems had surpassed its capabilities, and it remained primarily an operating system for students and hobbyists.
Simplified: In April 2000, MINIX became free/open source software under a permissive free software licence, but by this time other operating systems were much better, and it was used as an operating system for students and hobbyists.