To learn more developers can visit http://www.hopstop.com/freeapi/
 “HopStop is currently the most used site for mass-transit directions in the United States and receives nearly 1 million visits each month. While we are proud of the success of HopStop.com, our announcement today indicates our desire to make it easier for developers to build new tools or applications on HopStop’s XML Web Service architecture.”, said Chinedu Echeruo, CEO and Founder of HopStop

Benefits
1. Enrich the user experience on your website by providing customized subway, bus and walking directions to any location in New York City, Boston, Chicago, Washington D.C and San Francisco.

2. Improve the "stickiness" of your website by adding value and interactivity.

3. Leverage the power of HopStop technology while you retain your website's look-and-feel and control over the user's experience.
Developers who want to use the API to create new location-based service or to mashup with existing websites or applications can sign up for a free license key which allows for up to 1,000 transactions a day.

The service can be accessed through one of the three ports implemented: SOAP, HTTP POST, or HTTP GET. Sample scripts written in Perl, PHP, Classic ASP, ASP.NET or VB are also available for developers. Please click on the link below to learn more and sign up for a free account: http://www.hopstop.com/freeapi/

About HopStop

HopStop provides door-to-door directions to city residents and tourists via public transportation systems.  The company is building the first national network to facilitate inter-city and intra-city travel using mass transit systems. The Company’s services are currently available in New York City, Chicago, Boston, San Francisco and Washington D.C.
For more information:

Source: GISuser