wimlib is a C library for creating, modifying, extracting,
and mounting files in the Windows Imaging Format (WIM files).
wimlib and its command-line frontend 'wimlib-imagex'
provide a free and cross-platform alternative to
Microsoft's WIMGAPI, ImageX, and DISM.

Additional non-required dependencies:

libfuse (optional but recommended):
cdrkit (optional)
mtools (optional)
cabextract (optional)
