"The most important difference is that Serena OS is far closer to the POSIX standard in terms of functionality and behavior than the original Amiga OS was. This is most noticeable (from the viewpoint of an app developer) in the sense that Serena OS does full resource tracking. This means that the OS automatically reclaims resources such as memory when an application terminates."

https://amiga-news.de/en/news/AN-2024-08-00046-EN.html