object library

hello, I have some game concept, but I need to know if I could do something like this:
I want to setup a file called library.blend, and fill it with lots of objects like weapons, vehicles, etc.
and from another file, called something like game.blend, i should be able to add any object just by typing its name.
eg, if I type katana, and there is an object called katana in library.blend, it is added to the current game scene.
Is it possible?
sorry for my bad english

kindof,
youd need to have all the objects linked in to begin with in a background layer,
then while your in the game you could add objects to visible layers as you go.

dynamically loading/converting is not impossible but not supported.

It is possible to code a non-game python script that could locate and link all objects automatically? so I could run it once each time I want to update the library.

yep, its possible but I dont think its needed, you could link in an entire scene and use it as a set with all the objects on a background layer.
This way you can add any objects you like there and on load all of them will be added.

and a last question: is there any noticeable slowdown on having thousands of objects on a deactivated background layer?

from my usage the slowdown is only at startup since the objects are converted to BGE objects (every vert face etc)
So if the initial startup time is acceptable then it should be ok.