The FMI 3.0 Implementers' Guide is a free resource intended to give non-normative recommendations and guidance to implementers of the Functional Mock-up Interface standard version 3.0. All guidance is based on FMI 3.0 unless otherwise noted or applicable. This is a development version of the guide that has not been reviewed or finalized in any way. All of the content is to be considered non-normative and shall not be considered to supplant any normative statement in the FMI 3.0 standard. Releases and issues can be found on github.com/modelica/fmi-guides.