Reference

Treemaps for space-constrained visualization of hierarchies
http://www.cs.umd.edu/hcil/treemap-history/
Werkema.com - Software - SpaceMonger
http://www.werkema.com/software/spacemonger.html

via

MOONGIFT - Dynamic treemap layout comparison
http://oss.moongift.jp/intro/i-836.html
MOONGIFT - SpaceMonger
http://fw.moongift.jp/intro/i-835.html