WorldPay
WorldPay is a complete, vertically-integrated gateway that provides real-time financial transaction processing and management. They also facilitate the application for a credit card merchant account (American Express, MasterCard and VISA). WorldPay requires that an SSL certificate be obtained by the end-user.
More information about WorldPay can be found at: http://www.worldpay.com
E-xact
E-xact is a transaction processing gateway that provides real-time financial transaction processing and management. E-xact requires that the end user obtains an SSL certificate and a US or Canadian merchant account. The E-xact solution requires you to install and configure connection software.
More information about E-xact can be found at: http://www.e-xact.com/
InternetSecure
InternetSecure is a transaction processing gateway that provides the same style of services that E-xact does. A merchant account is not required, because InternetSecure provides an in-house merchant account that is tied to the user's business bank account. An SSL certificate is not required, as all credit card information is processed on InternetSecure's servers. You do not have to install any additional software, however, some order form modifications must be made.
More information about InternetSecure can be found at: http://www.internetsecure.com/
CyberCash
Cybercash is another transaction processing gateway. While Cybercash requires a merchant account, they have partnered with various banks and offer an online application form that can give a user approval in minutes. An SSL certificate is required as credit card numbers are entered on the end user's website. CyberCash requires a software component to be installed.
More information about CyberCash can be found at: http://www.cybercash.com/