SiSMS is a program for reading SMI/SMO files, which are archived SMS messages generated by Siemens mobile phones. It allows you to open and save messages you have downloaded to your computer from your mobile phone. It features EMS support, built in addressbook, printing and saving of messages, searching in SMI/SMO files, etc. SiSMS is released under the terms of the Open Software License v. 2.1 and as such can be freely used and modified.
Everything best is done for the moment to switch to Open Source. SiSMS is an existing program and currently it is in initial stage of conversion. Please, check back later or search the Internet for SiSMS.
Siemens SMI/SMO files are binary encoded SMS messages as generated by the Siemens mobile phones (presently BenQ-Siemens). Apart from the actual SMS message (or messages for multi-part concatenated SMSs) they hold information for file type, message type/status, message date/time stamp and so on. For more information see the document Siemens SMI/SMO File Structure.