Perl is a script programming language that is similar in syntax to the C language and that includes a number of popular UNIX facilities such as SED, awk, and tr. Perl is an interpreted language that can optionally be compiled just before execution into either Ccode or cross-platform bytecode. When compiled, a Perl program is almost (but not quite) as fast as a fully precompiled C language program. Perl is regarded as a good choice for developing common gateway interfac e (CGI) programs because it has good text manipulation facilities (although it also handles binary files).
	Java is a programming language expressly designed for use in the distributed environment of the Internet. It was designed to have the "look and feel" of the C++ language, but it is simpler to use than C++ and enforces an object-oriented programming model. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. It can also be used to build a small application module or applet for use as part of a Web page. Applets make it possible for a Web page user to interact with the page.
	Secure Shell (SSH), sometimes known as Secure Socket Shell, is a UNIX-based command interface and protocol for securely getting access to a remote computer. It is widely used by network administrators to control Web and other kinds of servers remotely. SSH is actually a suite of three utilities - slogin, ssh, and scp - that are secure versions of the earlier UNIX utilities, rlogin, rsh, and rcp. SSH commands are encrypted and secure in several ways. Both ends of the client/server connection are authenticated using a digital certificate, and passwords are protected by being encrypted
	Apache is a freely available Web server that is distributed under an "open source" license. Version 2.0 runs on  most UNIX-based operating systems (such as Linux, Solaris, Digital UNIX, and AIX), on other UNIX/POSIX-derived systems (such as Rhapsody, BeOS, and BS2000/OSD), on AmigaOS, and on Windows 2000. According to the Netcraft (www.netcraft.com) Web server survey in February, 2001, 60% of all Web sites on the Internet are using Apache (62% including Apache derivatives), making  Apache more widely used than all other Web servers combined.
	rsync is a file transfer program for Unix systems. rsync uses  the "rsync algorithm" which provides a very fast method for  bringing remote files into sync. It does this by sending just the  differences in the files across the link, without requiring that  both sets of files are present at one of the ends of the link  beforehand.