Ordered hashes for Perl

 This module implements an ordered hash, meaning that it associates keys
 with values like a Perl hash, but keeps the keys in a consistent order.
 .
 Tie::Hash::Indexed is very similar to Tie::IxHash. However, it is written
 completely in XS and usually about twice as fast as Tie::IxHash. It's quite a
 lot faster when it comes to clearing or deleting entries from large hashes.
 .
 However compared to Tie::IxHash, only the plain tying mechanism is supported.