This is an alternative implementation of the su binary for Superuser on Android.
This implementation is compatible with the original su binary but differs in
the following:
o it doesn't use the am command for notifying Superuser.
  The old C++ code crafting intent body is used instead. The code supports
  Android versions up to ICS inclusive.
o it sets LD_LIBRARY_PATH to the value copied from the parent process
  on ICS or higher.
o it is linked dynamically.
o it tracks both su.db and permissions.sqlite databases when checking
  whether the caller is allowed to call su. Thus, all Superuser versions are
  supported.

The implementation is compatible with Superuser 3.1.3 or less.