Momentum for the Isis digital wallet platform is starting to gain in speed again as four more payment system suppliers have signed on to the project.

VeriFone, Ingenico, ViVOtech and Equinox Payments have all agreed to integrate and support the Isis Mobile Commerce Application on current and future products. They join the original backers of Isis: AT&T, T-Mobile USA and Verizon Wireless.

None of the partners here have revealed any real specific details as to how they'll be integrating Isis, but they do have a common goal: accelerate the mainstream adoption of mobile commerce.

Part of how this will be done is to enable Isis technology on the products (mostly payment terminals) offered by the aforementioned quartet of new suppliers.

Interested merchants will also have to step up by installing a combination of new payment acceptance systems, NFC add-on devices, and software to certain existing devices already in the wild.

Isis, overall, has hit a stumbling block or two in the last year -- mainly just being slow getting out of the gates while several other digital payment solutions (from the likes of Google, Visa, and PayPal, among others) have gained interest quickly.

Last May, Isis changed directions from originally being an alternative option to credit cards with charges going directly to one's phone bill to being a more general mobile wallet.

That idea heated up in July 2011 when Isis inked deals with Visa, MasterCard, Discover, and American Express. That must have offered some encouragement to AT&T, T-Mobile USA and Verizon Wireless, as the trio reportedly infused $100 million more into the development of the Isis platform.

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