Normally on a desktop system users are using something called "glibc". This is a fairly sizable package, approximately two to three megabytes. It can be simplified or minimized by using something called "uClibc", an embedded replacement of glibc. The uClibc is under active development and is being specially adapted for embedded systems. There are some desktop systems which are built using uClibc, and it is used in embedded applications to build user applications. "Printf," "malloc," a kernel system, and other utilities are included which makes it easier to build applications. There are other libraries that may be needed such as a math library, encryption, or compression libraries.