extracting ".arc" and ".zip" files

[vapid nihility]

 	Can I extract ".arc" and ".zip" files from within Unix.
The files I wish to extract came from wuarchive.wustl.edu, "an msdos 
archive site". I am really only interest in source code, but I
have no idea how to obtain source code for the msdos operating
system. At this stage dos appears to be the best approach, because it
enables effective use of low power hardware reducing the cost of my
project. I plan to program a very simple Point of Sale Terminal, which
utilise existing dbase and worksheet programs as much as possible.

I has been about 5 years since I have been in the PC game. For most
application I program, which are in Unix, there seems to be an enormous
bases of public source code to begin from.

-Tim.