TRL-5 - Technology Development
TRL-7 - Technology Demonstration

The ET has flown into space
Tail sitting aircraft and spacecraft have been demonstrated
Aerospike engines have been demonstrated
Foldaway wings aboard rocket launched vehicles have been demonstrated
Inflatable heat shields have been demonstrated.
Airplane towing gliders have been demonstrated
Recovery of spacecraft by tow planes from orbit have been demonstrated
Parallel staging has been demonstrated
Feeding propellant from one parallel staged element to another has
been demonstrated.

http://www.scribd.com/doc/31261680/Etdhlrlv-Addendum