Comment 6 for bug 691839

Just a quick answer (I'll search for more details later):

Seems that there hasn't been a spec written yet for the measurement tool (beyond what is on the blueprint page and the linked reports). Work to be done? ;) Maybe a search in Inkscape's Wiki reveals some orphaned pages… <http://wiki.inkscape.org/wiki/index.php/Inkscape>.

About the tech drawing: the tool has been committed into Inkscape's sources, but it is disabled (as requested by its author, due to the unfinished state of its UI). See <http://www.libregraphicsworld.org/forum/viewthread.php?thread_id=64&pid=170#post_170> for a recent discussion, including a teasing screencast provided by Alexandre Prokoudine and information on how to enable it (needs some edits in the source files, and recompiling).