Librecad is now qcad (librecad is defined elsewhere).
Thoggen is no more.
Deleted on 2013-04-10 by Martin Pitt
does not build against current glib, hal, and dbus, dead upstream, uses old
gstreamer, removed from Debian testing, long-standing RC bugs.
(https://launchpad.net/ubuntu/raring/amd64/thoggen)
ruby-prof is not in Trusty.
Deleted in trusty-release on 2014-03-18 (Reason: (From Debian) ROM;
Unfit for release; Debian bug #735472)
https://launchpad.net/ubuntu/+source/ruby-prof/+changelog