The vocabulary loader searches for vocabularies in one of the root directories:

vocab-roots

The default set of roots includes the following directories in the Factor source directory:

•	core - essential system vocabularies such as parser and sequences. The vocabularies in this root constitute the boot image; see Bootstrapping new images.
•	basis - useful libraries and tools, such as compiler, ui, calendar, and so on.
•	extra - additional contributed libraries.
•	work - a root for vocabularies which are not intended to be contributed back to Factor.

You can store your own vocabularies in the work directory.
Working with code outside of the Factor source tree