This information is provided by someone familiar with SAM but little knowledge of Folk. Some claims about Folk may be regrettably inaccurate.

The Syndicated Actor Model (SAM) is a system for working with software actors that is convergent with Folk.

SAM is not a single program or library but a data language and protocols with a set of implementations for different languages. There is a common set of features with each language as varying in how much of the feature set is supported. Implementations with a simple feature set use the Syndicate protocol to communicate with actors in other languages that provided missing functionality.

Folk has a Database of statements and SAM Dataspaces of asserted facts.

Folk is primarily written in Tcl and SAM has a basic Tcl implementation.

Both use a reactive programing paradigm:

# Folk
When $program has resolved geometry /geom/ {
    Claim $editor has resolved geometry $geom
}

# Sycl
during "<resolved-geometry $program @geom #?>" {
  assert "<resolved-geometry $editor $geom>"
}

Folk is composed as a Tcl program. SAM is a composition of actors conversing using the Syndicate protocol.

Folk uses statements built from tokens. SAM uses the Preserves data language and relies on compound values such as lists, records (<some-label some fields …>), dictionaries, and sets.

SAM has distinct text-string, byte-string, and symbol data types, which is a pain to deal with in Tcl. Folk uses Tcl values.