1)   SMS and Pager Toolkit 4.1
SMS ActiveX Component for Windows, to send and receive SMS messages. Support for GSM modems and SMPP service centers. Samples included for VB, VC/C++, VB .NET, VC# .NET, ASP, ASP .NET, Java, PHP. Product of the Year at http://www.smssolutions.net

 2)   SMS and MMS Toolkit 5.0
Send and receive SMS messages via a GSM/GPRS modem, HTTP-POST provider or SMPP provider. Send and receive MMS messages via MM1 (GPRS), MM4 (SMTP) or MM7 (XML/SOAP). Samples for VB, VC++, VB.NET, VC#.NET, ASP, ASP .NET, Javascript, PHP and more

 3)   SMS-it 3.7.6
SMS-it allows you to send SMS to a mobile phone from your computer. It sends through a modem, the internet (free SMS) or an attached mobile phone. SMS-it can integrate with MS Outlook and synchronize the inbox to store the messages.

 4)   HS GSM SMS C Source Library 1.3
HS GSM SMS is a C source library. It provides a PC based user application with access to a mobile phone's Short Message Service (SMS) function, according to ETSI standards: GSM 07.05 (ETS 300 585) (use of DTE for SMS), GSM 03.40 (SMS)