The military applications of self-replicating micro- and nanotechnology were realised very early in the Interplanetary Age, especially against soft targets (organic materials and unprotected infrastructure particularly). Such military nanoswarm weapons became popularly known as Khaki Goo. But defence systems against aggressive nanoswarms were quickly developed, and in any case early khaki goo was limited in its usefulness by the amount of stored energy each bot could carry, and in many other ways.
In space warfare for instance an Interplanetary Age nanoswarm weapon did not have enough stored energy to quickly assemble or disassemble iron-hulled craft, for instance. All hull ports and openings could be easily protected by periodic EMP sterilisation, although this would decrease the utility of any data flow through such a port.
Habitats were more vulnerable, however, as so much material must flow in and out of an inhabited structure; all commodities had to therefore be nanoscopically scanned using nanoscouts and other blue goo defences. The logistical problems with such tiny scanning led to the virulent Nano-outbreaks in 540 AT, which were largely attacks on personnel, consumables and data resources. Once a small population of self-replicating Khaki goo had found a toe-hold inside a ship or habitat, it was very difficult to eradicate.
On a planetary surface khaki goo, especially strains using bionanotechnology, could hide among native populations of micro-organisms until ready to attack. Blue goo was helpless against such sneak attacks, until the sophisticated forms of defences developed by GAIA became available.
Since that time defences and preventative measures have improved considerably so that attacks are rare; but many novel and advanced species of nano have appeared over the centuries, a constant test of the blue goo defences. In particular advanced forms of energy storage allow tiny devices to retain very large amounts of energy, enough to attack (or defend) almost any target.
A recent instance of a nanoswarm disaster is the one that occurred at Swallowflight, leading to the establishment of the Vela Immunity.
Nanoswarm weapons remain a constant danger, just as genetically engineered diseases remain a risk, and data viral infections likewise; all such forms of infection must be resisted by immune defences which are constantly upgraded.
Goo, Golden - Text by M. Alan Kazlev, from Anders Sandberg's Transhumanist Terminology A type of goo disaster, the strange name comes from an early Information Age hypothetical scenario. The idea was to use nanomachines to filter gold from seawater. If this process got out of control the result would be piles of golden goo (the " Wizard's Apprentice Problem"). This scenario demonstrated the need of keeping populations of self-replicating machines under control; it is much more common than grey goo, but also more manageable. Also Carbon Goo, Aluminium Goo, etc.
Goo, Green - Text by M. Alan Kazlev  A plague of bionano (non-drexlerian) goo; especially of strong biotic form. Green Goo outbreaks are (like Golden Goo) quite common, but easily managed, at least in those areas with good access to blue goo and equivalent.  Facetious term for biological life spreading throughout the galaxy. c.f. pink goo.  (archaic) The scenario of nanomachines or bio-engineered organisms used for human population control, either by governments or eco-terrorist groups (generally by sterilizing people through otherwise harmless infections).