This directory contains all the additional REQUIRED dependencies that JPEGView needs to compile.
Homepage: SourceForge Windows Template Library (WTL)
FYI: WTL cannot be included in the JPEGView source distribution, because Microsoft Public License is INCOMPATIBLE with GPL.
You can, however clone the submodule into this directory.
To build JPEGView and have it automatically find WTL, clone the submodule. (Alternatively, you can download a zip file from the WTL project page and extract it to a folder named wtl-sf)