One of the SmalltalkImplementations; intended for several operating systems. It's free for commercial use, and can compile to CeeLanguage for stand-alone executables. You can also inline other languages.
More information and the download can be found here: http://www.exept.deFrom the webpage:
''Smalltalk/X (ST/X) is a complete implementation of the Smalltalk programming language and development environment, providing:
Object Oriented Programming Language
Integrated Graphical Development Environment with Editors, Browsers, Debugger, etc.
Incremental Compiler and byte code interpreter + dynamic translator (jitter).
Static compiler, generating true binary class libraries (dlls) and executables.
Can generate very small footprint standalone executables which run w.o. image (hello world)
Extensive Class Library (>4500 classes) with many ready-to-use building blocks for Applications.
Provides Classes for many popular protocols (XML, SOAP, FTP, NFS...)
Builtin WebServer, Wiki, HTML with embedded Smalltalk etc.
License free (with a few exceptions), even for commercial work