OK, Lorenzo, I see what you mean.
At the KT Depository (Download link) you can access to some free content such as lots of nice materials and some 3D trees.
Some of the materials were created by the enthusiastic members of the KT community, others were transformed from (free) offerings of 3rd party products.
The 3D content is also the courtesy of 3rd party companies but adjusted to Kerky.
This does not sound much but considering that it is free, it's already a rich collection. Also the KT Team transformed a lot of other 3rd party content (trees etc) into KT but since they are commercial products of 3rd party companies, you can only access them if you can prove that you have purchased those products already. The KT Team's courtesy is that they made it perfectly usable in KT and this KT version then will be provided to you free.
Again, note that most of the content is created by the members themselves and shared selflessly but all of them have their own lives, jobs, families, friends etc. and this content is not made in masses like those of some commercial renderes.
With the smart use of the already existing "RPC" content you can already create beautiful scenes.
