BuildTool hooks into TD's Project/Build menu, provides a unique build number for every build and keeps track of date/time, machine name and user name. This information can be stored in the outline, external files or in a database (from build 1.09).
Read this TeaTalk article for information about BuildTool.
Version history BuildTool.log
CTD 1.51, Build 1.05 BTool15.zip
CTD 2000, Build 1.05 BTool20.zip
CTD 2.1, Build 1.05 BTool21.zip
TD 3.0, Build 1.13 BTool30.zip
TD 3.1, Build 1.13 BTool31.zip
TD 4.0 (2005), Build 1.13 BTool40.zip
TD 4.1 (2005.1), Build 1.14 BTool41.zip
(thanks to Niels Allerheiligen for creating this build)
Sourcecode (Changes and DLL for TD 4.2 included, no executable): BuildTool_Sources.zip
I will try to provide a version of BuildTool for TD 5.1 ASAP but there are currently problems with the DesignHookDLL interface which have not been fixed in SP1.