GNU/Linux is a very stable operating system and system crashes are virtually unknown. GNU/Linux, like Unix before it, is designed to be a multi-user, shared system. Simply because one user of the system runs an application that crashes, other users of the same system should not be affected. Also, most GNU/Linux applications have been in open development for many years with many developers working on and looking over the code. Bugs of course are not unknown, but they are usually quickly fixed within GNU/Linux, leading to a very reliable system.