How your manuscript handling system (MHS) works together with RQC. MHSs not mentioned here are not supported by RQC so far. If you need this to change, contact the makers of your MHS and point them to the RQC API definition.
Elsewhere:
Status: EasyChair is supported since 2016-09. It was the first MHS supported by RQC.
EasyChair support works via web scraping: RQC reads the same web pages that humans look at and pulls the information from them. This means the RQC implementation may break when the EasyChair folks modify the structure of the web pages. Such breakage happens about once every one or two years and will be rapidly repaired as soon as we notice it (which is usually the next work day).
Status: HotCRP is supported since 2017-07.
In contrast to EasyChair, HotCRP has a proper API by which RQC can grab the reviewing data. It uses a "flat" model where all submissions are treated the same, which means that sophisticated use cases of HotCRP may not be covered adequately.
Status: A plugin is available for OJS 3.3.
It serves as the pilot implementation for RQC for journals.
(A version for OJS 3.4 will follow in due time.
If you are keen of getting it, please raise your hand.)
It maps editor roles as follows: - Any OJS journal manager assigned to a given submission will be level-3 editor in RQC. - Any OJS editor assigned to a given submission will be level-1 editor in RQC.