4. Interoperability between C and GNU Smalltalk

4.1 Linking your libraries to the virtual machine
4.2 Using the C callout mechanism		Calls from Smalltalk to C
4.3 The C data type manipulation system		Manipulating C data from Smalltalk
4.4 Manipulating Smalltalk data from C
4.5 Calls from C to Smalltalk
4.7 Manipulating instances of your own Smalltalk classes from C		Manipulating your own Smalltalk objects
4.9 Incubator support		Protecting newly created objects from garbage collections
4.6 Other functions available to modules		Handling and creating OOPs
4.8 Using the Smalltalk environment as an extension library		The Smalltalk environment as an extension library