Yahoo continues to open up its online services to Web developers Yahoo will release new and enhanced application programming interfaces (APIs) for four of its online services in the coming months, the Sunnyvale, California, company plans to announce on Tuesday at the O’Reilly Emerging Technology Conference in San Diego.The move is part of Yahoo’s ongoing effort to open up its online services to Web developers, said Ash Patel, Yahoo’s chief product officer.By providing APIs, Yahoo allows external developers to extend the functionality of its online services and create new applications on top of them. The two new APIs will be for the Yahoo Photos online service for sharing digital photos and for the Yahoo Calendar online calendaring service.Meanwhile, Yahoo will release enhanced APIs for the Yahoo Shopping comparison shopping engine and for the MyWeb 2.0 social bookmarking service.More details on these APIs and their availability will be provided later on the Yahoo Developer Network Web site (http://developer.yahoo.net). The APIs will be free for developers to create non-commercial applications. Those interested in creating commercial applications should contact Yahoo to work out a deal.Yahoo, which already provides a variety of APIs for a set of its online services, plans to continue opening up its platform to external developers in a systematic way, Patel said.Yahoo also plans to launch a gallery of applications built on top of its online services at http://gallery.yahoo.com. Software DevelopmentDatabasesTechnology IndustrySmall and Medium Business