Does Factor support multiple OS threads?
Currently, no. Factor's threading model works somewhat similarly to Erlang's, with the important difference that there is only one heap, and the runtime (virtual machine) always runs in a single OS thread. The VM isn't currently thread-safe, though it will be made so in the future. Certain language features, such as word properties, currently pose challenges for making Factor thread-safe. Because everything is run in a single OS thread and there is no direct efficiency gain, Factor threads are most useful for things like executing parallel I/O operations that involve waiting.
