Wikipedia
Systrace is a computer security utility which limits an application's access to the system by enforcing access policies for system calls. This can mitigate the effects of buffer overflows and other security vulnerabilities. It was developed by Niels Provos and runs on various Unix-like operating systems.
Systrace is particularly useful when running untrusted or binary-only applications and provides facilities for privilege elevation on a system call basis, helping to eliminate the need for potentially dangerous setuid programs. It also includes interactive and automatic policy generation features, to assist in the creation of a base policy for an application.
Systrace used to be integrated into OpenBSD, but was removed in April 2015 It is available for Linux and Mac OS X, although the OS X port is currently unmaintained. It was removed from NetBSD at the end of 2007 due to several unfixed implementation issues. As of version 1.6f Systrace supports 64-bit Linux 2.6.1 via kernel patch.