eXtensible ARchiver
A fork/clone of the subversion xar repository from http://xar.googlecode.com/svn/ that includes several enhancements and bug fixes including very basic command line signature support. This is not a general purpose package and exists only as a dependency for ld64. As such, on Darwin, it is entirely statically linked, except for libcrypto, which you must ensure gets resolved to /usr/lib/libcrypto.dylib when this library is consumed.