It's part of exploit development.
A hacker first discovers a problem. For example, he might notice that while logging onto email, if he types in a username 1000 bytes long, the server crashes.
So what the hacker does is figure out how to manipulate the overflowing bytes to cause program execution to "jump" somewhere in the buffer.
The hacker then writes code to open up a command-prompt (aka "shell"), and interact with that command prompt over the network. This is called "shellcode". It's the shellcode that that you see above.
The hacker the combines this all into an "exploit" program that can be used to hack into a system by simply specifying an IP address of the victim.
The hacker than scans a network looking for vulnerable systems. When he finds one, he then runs his exploit against it, breaks in with a shell prompt. This is realistically shown in the 2nd Matrix movie.
Once the hacker has the command prompt, he can send arbitrary commands to the system. He might create his own user account. He might download the password file. He might dump credit card numbers from the database.
That shellcode you see above is specified in C, because that's what most exploits are written in. But it's easily translated to other popular languages that have similar syntax in C.
The shellcode specifically is designed for NetBSD running on x86. NetBSD is an operating system system closely related to Mac OS X and more distantly related to Linux. It used to be popular for small computers, but has largely disappeared these days. So this is pretty useless.