PortalPlayer. Throughout 2006, Rockbox ports were made available for a variety of iPod models. Beginning in 2007, ports became available for a large number of additional ARM based targets, including players from Sandisk, Toshiba, Olympus and Philips in addition to newer Apple and iRiver players based on a variety of ARM7, ARM9 and ARM11 series processors. During this time, extensive work was conducted optimizing open source audio decoders for each of the ARM series processors. In 2008, porting began to processors based on the MIPS architecture. In 2010, work began on supporting "hosted" architectures where Rockbox runs as an application inside of more complex operating system. all Rockbox ports have been accomplished by reverse engineering with little or no manufacturer assistance. As free software, many Rockbox developers and supporters hope to eventually see official manufacturer support for new ports, or at least unofficial assistance in porting Rockbox to new devices. Only a few companies have expressed interest in Rockbox, and none have officially contributed code to the project or included it with their hardware. The Sansa e200v1 port is the first to be started at the request of the hardware manufacturer, who gave the Rockbox team samples of their devices. Rockbox is continuously developed, with new Git builds being released after every source change, and stable releases every 4 months for targets deemed sufficiently mature. Additionally builds are often available to developers of unsupported targets, which, while somewhat functional, are typically not ready for general users due to incomplete features or poor stability. As of 2019, there have been no new ports released. Future Rockbox is targeted primarily at digital audio players, rather than the much more powerful general-purpose devices (such as smartphones and tablet computers) that have been increasing in popularity since 2010. Some authorities expect the former class of devices to become obsolete in the next few years. Daniel Stenberg, a founder of the Rockbox project, envisions the project evolving away from a standalone Rockbox operating system to Rockbox as a media player application that runs under mobile operating systems, such as Android, iOS, Sailfish OS or Tizen: A project to port Rockbox to run as an application under a full-fledged operating system was accepted for Google's 2010 Summer of Code and completed. Currently, Rockbox runs on Android based players, but integration into Android and conversion to work with touch based devices is ongoing. Subsequently, an anonymous Chinese