Each version of STM has extensive online help,
If STM is running, you access online help from the Help pulldown menu (xstm and mstm) or by executing a help command (cstm).
General Help (Platform, User Interface)
The help systems for the platform as a whole have been translated to the Web pages are available from this page:
Each interactive tool (expert tool, firmware update tool, and utility) has its own online help system. Many (but not all) of these help systems have been translated to the Web and are available from this page: