Opera, the maker of the very popular mobile browser, released software tools today to allow developers to build widgets for mobile devices. The idea is similar to iPhone’s emphasis on creating applications for the Safari browser and likely is being positioned as an alternative to Google’s (NSDQ: GOOG) Android efforts. Marshall Kirkpatrick from ReadWriteWeb compared it to Apple’s (NSDQ: AAPL) iPhone SDK, which requires that applications be distributed exclusively through Apple and that they pay a $99 application fee. He wrote: “Opera SDK built widgets appear to be much more open and free. Opera posted details on its blog today that said its Opera Widgets SDK provides tools, libraries, documentation and examples on how to make them. The Opera widget is based on the Opera browser, so it uses all the standard web technologies, like HTML, Java and Ajax, and works on platforms such as Windows, Linux or Mac, and across devices, such as mobile phones, desktops and game consoles. The users download the widgets to their device and run them locally.

Opera provides more info in a long Web video (Trust us, it’s worth watching to see the Opera developer wearing a hand-made T-shirt with a heart drawn around the words Opera + Widgets and a bow and arrow shooting through it):

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