Work of scaner mostly depends on it's type - SCSI/LPT/USB/..., because TWAIN-interface is supported. Also you can find information about scanners and OS/2 here.
The development of software for eComStation is profitable: a) system API is effective and considered. b) The market is not so infinite as Windows. All eCS users know about your product. c) Every developer is influencing on the OS significantly.