There have been several Questers supplements published, mostly as short PDFs. They are available from the usual sources (see right).
The Book of Bewildering Beasts
A compilation of earlier short products. This 32-page book has 44 monster write-ups in the QMR style, blending danger, humour and downright weirdness. It also includes an updated list of common creature Qualities and a gazetteer of monsters specific to the various regions of the setting.
Character creation in Questers of the Middle Realms is simple, but so open and flexible that it can be daunting. This 6-page mini-supplement provides lists of different character aspects: occupation, homeland, talents, skills, personality traits, etc. Skim the entries for inspiration or roll randomly. It also introduces six divisions of magic to help you home in on the right Arcane Quality.
Ten Magical Thingies, vol 1
Ten magic items to expand your game, both familiar ones with a QMR spin and new creations: Corset of Defence, Delmolio’s Patent Cure-all, Disposable Armour, Divisibility Potion, Glamour Crystal, Ninmuzi’s Guardian, Peril Protection Pendant, Portable Steed, Sixpence People, Stormblade.