[CMake] Complicated dependency handling between linux & windows

[Robert Dailey]

Currently I only use CMake on Windows. I handle third party
dependencies by building them myself, stuffing the compiled binaries &
includes on an FTP server, and having CMake download them locally so I
can link against them during generation.

However, for Linux this process won't really be very helpful. Due to
the vast number of distros and such, maintaining my own compiled
binaries for all of them would quickly become unmaintainable. Ideally
I'd just use the Linux package manager to handle those dependencies
and just use FindPackage modules to find them. However, the inverse
problem will then occur: Windows does not have a package manager, so
it's far more convenient to have CMake download my compiled packages
for third party dependencies instead of installing them one by one and
using find package modules.

Is there a single, great way to handle third party dependencies
conveniently and mostly transparently between Windows & Linux?