A version of QemuLator from Daniele Terdina for 68K Macs and for PowerMacs. A version for OS X is also in the early stages of development at the time of writing (March 2010). Further details from the author's website at:
http://www.terdina.net/ql/MacQL.html
This is a version of uQLx ported to Mac OS X by James Weatherley. Download it here
Jerome Vernet has prepared a version of uQLx for Mac OSX (and the associated XCode Project with source). X86 Snow Leopard Build (Snow Leopard is a current version of the Mac operating system OSX), but should work on Leopard (earlier version). Maybe not on PPC (andian... XCode 3 Project). Available to download at:
http://www.megupload.com/?d=E0B5DV5H
Jan Venema created a version of QLay for Linux systems. Further details and downloads from Jan's website at
http://web.inter.nl.net/hcc/A.Jaw.Venema/
uQLx is a derivative of the emulation engine used in QemuLator. uQLx is produced by Richard Zidlicky to run on Linux/Unix platforms. Further details and download from:
http://www.geocities.com/SiliconValley/Bay/2602/
Or from Fabrizio Diversi's website
QDOS4Amiga is a QDOS emulator for the Commodore Amiga, by Rainer Kowallik and Mark Swift. It is freeware. Up to date copies may be obtained from most Ami-Net sites, or get it here:
http://www.dilwyn.me.uk/emu/
QDOS Classic for Amiga is a QL emulator for the Commodore Amiga by Mark Swift. QDOS Classic for Amiga is closely related to QDOS Classic for Q40 by the same author (see below). This emulator is freeware. Get it from:
http://www.mswift.unisonplus.net/ql/index.html
QLem is a rather old freeware software QL emulator for some Atari computers, by Johan Klockars. There is an associated QL floppy disk transfer utility, plus an associated utility called Tos4QL which can run some TOS (Atari operating system) programs on a QL. Details from the Ancient File Library at:
http://www.devili.iki.fi/pub/emulators/Sinclair/QL/
Originally produced by the Futura Datasenter in Norway, this emulator card for Atari ST computers then became available in various versions from Jochen Merz Software. The emulators can run QDOS or a special versionof SMSQ/E. Further details from Jochen Merz Software at the page below (when you get to the page, click on "SMSQ/E For Ataris" link):
http://smsq.j-m-s.com/
The Q40 and Q60 systems (collectively called Qx0) are advanced QL derivatives from Peter Graf in Germany and D&D Systems in England. Further details from:
http://www.q40.de
It has two operating systems - it is supplied with a special SMSQ/E version, and can also run a version of QDOS using the QDOS Classic system from Mark Swift's website at:
http://www.mswift.unisonplus.net/ql/index.html