Simplify the following text for a Grade 13 native English-speaking person.
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 mostly used as an operating system for students and hobbyists .