From SELinux Wiki
SELinux Project Wiki
This is the Security Enhanced Linux (SELinux) project page. Here you will find resources for users, administrators, vendors and developers.
For an account, send email to jmorris AT namei.org.
What is SELinux
SELinux is a security enhancement to Linux that allows users and administrators more control over which users and applications can access which resources, such as files. Standard Linux access controls, such as file modes (-rwxr-xr-x) are modifiable by the user and applications that the user runs whereas SELinux access controls are determined by a policy loaded on the system and not changeable by careless users or misbehaving applications.
SELinux also adds finer granularity to access controls. Instead of only being able to specify who can read, write or execute a file, for example, SELinux lets you specify who can unlink, append only, move a file and so on. SELinux allows you to specify access to many resources other than files as well, such as network resources, interprocess communication (IPC) and so on.
For more information about SELinux see the <FAQ> and other resources listed here.