WIL language extenders are among the most useful parts of the WIL language. Network connectivity, special arithmetic operations, and other capabilities can be added to WIL with extenders.

Extenders are often available on the web site : http://www.winbatch.com/download.html. They may be downloaded from there. The most widely used extenders are included on the distribution CD-ROM in the 'Extenders' subdirectory.

Software developers who want to create custom extensions to the WIL language may purchase a development kit called "WIL Extender SDK”. The actual extender must be written as a DLL using C or C++.

Each individual extender has a help file that explains how to use the functions in it.