The primary package referred to as Pool is Pool (Kupries). However, see also
What: Pool (Leunissen) Where: See contact Description: Tcl only package for managing pools of discreate items. Updated: 06/2002 Contact: <URL: mailto: e dot leunissen at hccnet dot nl >
I think this is the same package, as the tcllib struct::pool package. http://tcllib.sourceforge.net/doc/pool.html
Yes, Eric submitted this to tcllib, and it was included.