Evidencetracplugin is a project mainly written in PYTHON and SHELL, it's free.
Plugin that adds Evidence Based Scheduling essentials into your trac
== Introduction
Go read Joel's blog - http://www.joelonsoftware.com/items/2007/10/26.html
== Version
It is still in early development
== Requirements
Timing And Estimation Plugin - http://trac-hacks.org/wiki/TimingAndEstimationPlugin
== Install
http://trac.edgewall.org/wiki/TracPlugins#InstallingaTracPlugin