HS GSM SMS is a C source library that provides a PC-based user application with access to a mobile phone's Short Message Service (SMS) functionality, according to ETSI standards: GSM 07.05 (ETS 300 585) - "Use of Data Terminal Equipment - Data Circuit terminating; Equipment (DTE - DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)" GSM 03.40 - "Technical Realization of Short Message Service - Point-to-Point

HS SMTP LITE is a software library in C (supplied with full source code) which implements the client side of Simple Mail Transfer Protocol (SMTP) over TCP socket layer according to RFC 821. Support for transfer of basic message header and text is provided. HS SMTP Library incorporates the necessary state machine, transparency procedures, and server response processing required to comply to a simple and robust SMTP client implementation.

HS POP3 Lite is a software library in C (supplied with full source code) which implements the client side of Post Office Protocol Version 3 (POP3) over TCP socket layer according to RFC 1939. Among other features, the library supports user authentication, reception of basic internet headers and text, message deletion and statistics. HS POP3 Library incorporates the necessary state machine, transparency procedures, server response processing etc.

HS NTP is a software library in C (supplied with full source code) which implements the client side of Network Time Protocol (POP3) over UDP socket layer according to RFC1769 and RFC1305. HS NTP Library allows a user application to synchronise local system time to remote NTP server time.