View is a pure tcl TclOO interface to metakit with advanced relational functionality.
It's one of Wub's utilities, but useful enough to stand alone. It can be sourced here: [L1 ]
and perused here: [http://code.google.com/p/wub/source/browse/trunk/Utilities/View.tcl].
Documentation's thin on the ground, but View follows the mk4too interface, with a few additional functions suggested by analogy with dict and oomk.
CMcC is its current custodian, but help is welcome.