Here is a list of all files with brief descriptions:

flatom.cpp	Definitions for handling the t_atom type and lists thereof
flatom_part.cpp	Definitions for handling the t_atom type and lists thereof
flatom_pr.cpp	Definitions for printing and scanning the t_atom type
flattr.cpp	Attribute handling for the flext base class
flattr_ed.cpp	Attribute editor (property dialog) for PD
flbase.cpp	Implementation of the internal flext base classes
flbase.h	Internal flext base classes
flbind.cpp	Functionality for symbol-bound methods
flbuf.cpp	Implementation of the buffer abstraction class
flclass.h	User accessible flext base classes
flcontainers.h	Lock-free container classes
fldefs.h	This file includes all the #define header files
fldefs_attradd.h	This file contains all #defines for actual usage
fldefs_attrcb.h	This file contains all #defines for actual usage
fldefs_attrvar.h	This file contains all #defines for actual usage
fldefs_hdr.h	This file contains all #defines for actual usage
fldefs_methadd.h	This file contains all #defines for actual usage
fldefs_methbind.h	This file contains all #defines for actual usage
fldefs_methcall.h
fldefs_methcb.h	This file contains all #defines for actual usage
fldefs_meththr.h	This file contains all #defines for actual usage
fldefs_setup.h	This file contains all #defines for actual usage
fldoxygen.h	Doxygen definitions
fldsp.cpp	Implementation of the flext dsp base class
fldsp.h	Declares the flext dsp class
flext.cpp	Implementation of the flext base class
flext.h	This is the main flext include file
flfeatures.h	Detect version-specific features
flinternal.h	Definitions for internal flext usage
flitem.cpp	Processing of method and attribute lists
fllib.cpp	Code for handling of object (and library) creation functions
flmap.cpp	Flext container classes
flmap.h	Special map class (faster and less memory-consuming than std::map)
flmeth.cpp	Method processing of flext base class
flmsg.cpp	Message processing of flext base class
flmspbuffer.h	Definition of the Max/MSP buffer structure
flout.cpp	Implementation of the flext outlet functionality
flpopns.h
flprefix.h	Try to find out the platform
flproxy.cpp	Proxy classes for the flext base class
flpushns.h
flqueue.cpp	Implementation of the flext message queuing functionality
flsimd.cpp	Flext SIMD support functions
flsndobj.cpp
flsndobj.h
flstdc.h	Definitions to unite Max/MSP and PD notions
flstk.cpp
flstk.h
flsupport.cpp	Flext support functions and classes
flsupport.h	Flext support functions and classes
flthr.cpp	Implementation of the flext thread functionality
fltimer.cpp	Flext timer functions and classes
flutil.cpp	Implementation of the various utility functions
flxlet.cpp	Implementation of the variable inlet/outlet functionality