From Quang Tran Hong:
Pabx Billing System and Hotel Management is a Call Accounting system which is compatible with any PBX. The call detail record (CDR) can be programmed after installation and multiple CDR formats can be used at the same time. It has support both Serial interface and IP interface to Pbx and any call charge scheme and multiple call charge schemes (one per each telephone service provider). It includes online context-sensitive help, document in detail and contains more than 800 enterprises and hotels are using. Free for customer has less than 18 Extensions or Hotel with less than 6 Rooms.
What's new in this version:
Version 6.2 rel 2 has added some small new features.