The process of shutting down a Solaris system is critical. Using the init program to restart a system causes Solaris to perform a sequence of steps to shutdown services gracefully. The reboot command bypasses the runtime control scripts and can compromise data integrity. The sync commands synchronize the filesystem, flushing buffered data to disk.
Squid server is a popular open source GPLd proxy and web cache. It has a variety of uses, from speeding up a web server by caching repeated requests, to caching web, name server query , and other network lookups for a group of people sharing network resources.