1.2 Including GNU Smalltalk in your programs (legal information)

Believe it or not, Smalltalk is (also) a very good scripting and macro language. For this reason, GNU Smalltalk is distributed as a library that you can link your programs to. It's very simple: just include `gstpub.h', link to `libgst.a', and you're done. For more information on what to do in your program so that it communicates well with Smalltalk, relate to 4. Interoperability between C and GNU Smalltalk.

In this case, your program must be free, licensed under a license that is compatible with the GNU General Public License, under which the GNU Smalltalk virtual machine is licensed. The Smalltalk programs that we bundle with GNU Smalltalk (currently the browser and the compiler) are also subject to the General Public License, and must be made free.

On the other hand, the core GNU Smalltalk class libraries (standard classes, Blox, TCP abstraction, XML parsing) are released under the GNU Lesser General Public License. It is not necessary (although we would appreciate it) that programs that only use these libraries are made free.