A Californian company is to launch a product that to let developers create telephony applications they can embed in web pages.

Ribbit's back-end technology includes a software switch that essentially connects Internet-based voice communication services with mobile phones, landline phones and text messages. On top of that connection is the Ribbit APIthat lets developers build applications that unify the wide variety of communication methods.

Developers can build applications that include functions such as recording, sending and receiving voicemail, and making and receiving calls. The applications can be built using Flash, embedded into any site, and integrated into existing web-based services. The platform supports many existing VoIP platforms such as Skype, GoogleTalk and MSN.

Developers can charge end-users for the applications, and Ribbit can handle the billing for them. There are several ways developers can offer and charge for their products, and in some cases Ribbit will share revenue with developers.

Ribbit showed off one application a developer has created that embeds phone capabilities into Salesforce.com. By keying a code into a mobile phone, users essentially replace their current voicemail with Ribbit for Salesforce. Then users can listen to or see text transcripts of their mobile voicemail messages within Salesforce. They can send the messages to colleagues and tag them for easy sorting later.

Users can also make and receive phone calls through their Salesforce page. Such calls are automatically logged in their Salesforce application.

Ribbit for Salesforce will cost US$25 per user per month for end-users. It is currently in a private beta with more than 90 companies, and should be widely available in February, Ribbit said.

Salute America's Heroes, a veterans' association, has built essentially a call center application that lets veterans who work for the group make and receive phone calls while at home through a browser. The capability is integrated into a website that also hosts tools they use while making the calls. The capability allows the association to take on the cost of the calls rather than reimbursing workers for the use of their home phones.

Ribbit designed its own softswitch, which runs on Linux blades and has been certified in an Alcatel-Lucent lab to meet the capabilities and reliability that telecommunications providers typically require, said Ted Griggs, CEO and co-founder of Ribbit. Ribbit's network operations center is hosted by a third party in Virginia, and the company is working on opening one on the West Coast to offer geographic redundancies. It can add capacity simply by adding more servers.

Ribbit says that more than 650 developers are working on new applications, although on Friday only two were listed on the developers site. "Dozens" are near release, a few additional applications should be available on Monday, and many more should be available in the early months of next year, Ribbit said.