Velcro Rockets is an addon created by Erik Anderson, also known as Sputnik. It allows, through a config file system, to build individual rocket stages, multistaging being done in the .scn file. Velcro Rockets was partially built off of the CVEL GDPS code base.
Velcro Rockets most recent realease was Version 1.1
Velcro Rockets was intended to facilitate creation of other addons that required multistage or similar capabilities. There have been expansions to the launch vehicles included with Velcro rockets, including:
Velcro Saturns (v. 1.11) Velcro EELVS (v. 1.02) Velcro NEXUS (v. 1.0) Velcro N-1 (v. 1.0) Velcro Skybolt (v. 1.0) Velcro NOTSNIK (v. 1.01).
With Velcro rockets, a vessel can be attached as a parallel stage, a crossfeeding stage and a in-line stage. Stages can also be attached using CVEL.
-Stages will likely ignite spontaneously at high time accelerations
-After being edited with the scenario editor, all velcro stages in the scenario may put out only reduced thrust.
-Sometimes after being switched to from another vessel, the stage will put out only reduced thrust.