LispWorks® for
Macintosh® 
LispWorks for Macintosh is a full native implementation of ANSI Common Lisp for Mac OS X. There are two separately-licensed 32-bit and 64-bit products.
LispWorks (32-bit) for Macintosh supports Intel-based Macintosh computers as well as G3, G4 and G5 hardware and is available in three editions as described here.
LispWorks (64-bit) for Macintosh supports Intel and G5 hardware. It is available as Enterprise Edition, described here.
Download the product information sheet (here is a US Letter sized version).
To compare the various LispWorks editions and platforms visit the features page.
Below we describe some of the major features of LispWorks for Macintosh.
Graphical User Interface
The CAPI and LispWorks IDE run natively with Aqua look and feel through Cocoa.
Download the free Personal Edition to take a closer look!
Additionally, the Professional and Enterprise Editions offer as alternatives the GTK+ and Motif GUIs familiar to users of LispWorks for Linux.
Universal binaries
LispWorks (32-bit) for Macintosh is supplied as a universal binary which runs natively on both Intel-based and PowerPC Macintosh computers. LispWorks runtime executables can be universal or thin (mono-architecture) applications, as you require.
LispWorks (64-bit) for Macintosh is also supplied as a universal binary which runs natively on both Intel-based and PowerPC Macintosh computers. Universal binary versions of the 64-bit X11 and Open Motif libraries are also available from LispWorks. As well as thin applications, it is possible to build universal binary executable applications with LispWorks (64-bit) for Macintosh - contact Lisp Support for details.
Objective-C/Cocoa FLI
LispWorks for Macintosh includes an Objective-C API allowing you to create Objective-C classes and call methods. This allows you to use Cocoa functionality from Lisp.
CLIM
CLIM 2.0 is implemented only for X11/Motif. We have no plans to support CLIM under Aqua/Cocoa or GTK+.
Runtimes
With the Professional and Enterprise Editions you can build your LispWorks for Macintosh application as a runtime which is an executable, an application bundle or (for Intel Macintosh only) a dynamic library (.dylib).
Common SQL Database Support
Common SQL, available in the Enterprise Edition, offers sophisticated database access through ODBC or native interfaces to PostgreSQL and MySQL.
Macintosh Editor Emulation
The LispWorks Editor offers a choice of keys: Emacs, or standard Macintosh editor keys.
System Requirements
Here's more detail about the system requirements.