Exactly as for Blender Internal, Cycles materials can be linked from libraries. Every blend file containing linkable assets can be a library.
Linking materials is really a useful practice: let's say you have 20 different blend files with objects using an iron shader, and that at a certain point of your workflow you need to modify this iron material in all the files; by having this material linked in all the 20 files from a single blend is possible to update all of them at once by modifying just one shader in one file.
Just go to the File menu in the left part of the main header and select Link:
Browse to the directory where you store your library files and select the blend file you want to link the material from (for example, try the file
1301OS_02_library.blend
).Browse inside the blend structure, where the linkable assets are divided into subdirectories (shown as folders named as
Scene
,Mesh
,Material
,NodeTree
,Object
, and so on; note that the various folders...