This inheritance list is sorted roughly, but not completely, alphabetically:

[detail level 12]

CAircraftData
CAirportsData
Ccode
Cct_data_s
Cgz_header_s
Cgz_state
CHelpers
Cinflate_state
Cinternal_state
CJlCompress
CLatLng
►CQDialog
CdirDialog
CfileDialog
CImportAirportsDialog
CPropEditWidget
CSettingsDialog
►CQGroupBox
CExeControls
CXGroupGBox	A QGroupBox with a QGridLayout layout
CXGroupHBox	A QGroupBox with a QHBoxLyout layout
CXGroupVBox	A QGroupBox with a QVBoxLyout layout
►CQIODevice
CQuaZipFile	A file inside ZIP archive
►CQLabel
CXMessageLabel
►CQMessageBox
CMessageBox
►CQObject
CloadAptDat
CMainObject	The MainObject is an extended QObject, and the main "controller" for FGx
CMpTelnet
CTelnetSlave
CUnzipPrivate
CXProcess
CZipPrivate
►CQSettings
CXSettings	The XSettings is an extended QSetttings, but also includes most to the FGx configuration
►CQStandardItemModel
CXSettingsModel	The XSettingsModel is an extended QStandardItemModel, and the main "setting and state" for FGx
►CQStatusBar
CStatusBar
►CQThread
CSleeperThread
CworkThread
►CQTreeWidgetItem
CXTreeWidgetItem
►CQuaChecksum32	Checksum interface
CQuaAdler32	Adler32 checksum
CQuaCrc32	CRC32 checksum
CQuaZip	ZIP archive
CQuaZipFileInfo	Information about a file inside archive
CQuaZipFilePrivate
CQuaZipNewInfo	Information about a file to be created
CQuaZipPrivate
►CQWebPage
CXWebPage
►CQWidget
CAircraftWidget
CAirportsWidget
CCoreSettingsWidget
CExpertOptionsWidget
CFgxDebugWidget
CHeaderWidget
CLauncherWindow
CMenuWidget
CMetarWidget
CMpMapWidget
CMpMapXWidget
CNetworkWidget
COpenLayerWidget
CPilotsWidget
CPropsTreeWidget
CRenderingWidget
CTimeWeatherWidget
CViewLogsWidget
CViewLogWidget
CXBrowser
CXCommandPrevieWidget
CXDebugTreeWidget
►CQWizard
CSetupWizard
►CQWizardPage
CCompletedPage
CConfirmPage	The page that actually writes paths out, and reloads the cache
CFgExePage
CFgRootPage
CTerraSyncPage
CtagABC
CtagAD_AIRPORT
CtagAD_COMMS
CtagAD_RUNWAY
CtagAD_WINDSOCK
CtagGZHANDLE
CtagLOADITEM
CtagWORK
CtagWORKITEM
CtestExe
Ctm_unz_s
Ctm_zip_s
Ctree_desc_s
Cunz_file_info_s
Cunz_file_pos_s
Cunz_global_info_s
CUnZip	PKZip 2.0 file decompression. Compatibility with later versions is not ensured as they may use unsupported compression algorithms. Versions after 2.7 may have an incompatible header format and thus be completely incompatible
CXAero
CXOpt
Cz_stream_s
CZip	Zip file compression
Czip_fileinfo
CUnZip::ZipEntry
CZipEntryP
Czlib_filefunc_def_s