The primary way of obtaining the ExB source is via CVS (Concurrent Versions System).
If you have CVS programs installed, you can jump to the next section.
*NIX users can get them from CVS homepage.
For Windows users, you have a choice between WinCVS or Cygwin. Note: Cygwin is a Linux environment for Windows and comes with other useful packages besides CVS, when installing make sure you install the CVS package (in the 'devel' section).