The Italian Arduino Uno (£17.33 ex. VAT from RS Components) is perhaps the benchmark for small single-board computers.

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The BeagleBone Black (£35.16 ex. VAT from RS Components) is the open-source US equivalent of the Raspberry Pi from the non-profit BeagleBoard.org Foundation.

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The Banana Pi (£31.95 inc. VAT on Amazon) is a fork of the Raspberry Pi that uses different components, but attempts to provide as much compatibility as possible.

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PandaBoard is an open OMAP 4 processor-based mobile software development platform. The OMAP (Open Multimedia Applications Platform) processor was developed by Texas Instruments for portable/mobile multimedia applications. In 2012 TI announced that it was quitting the mobile processor business to concentrate on embedded platforms, and the future of OMAP remains uncertain. The PandaBoard can be obtained from DigiKey.

LinkSprite manufactures several single-board computers in the pcDuino range. This picture is of the pcDuino 3, which costs $59.99 (about £39) from LinkSprite.

Intel's Galileo Gen 2 is based around an Intel Quark SoC X1000 application processor and is compatible with the Arduino line of products. It provides more power and functionality for those already familiar with Arduino prototyping tools and costs around £50 (ex. VAT).

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Intel also offers the NUC series of kit products built into a mini-PC complete with case. The bare boards from this series are also available for purchase. Prices range from $128 to $419 (£83-£273).

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The Cotton Candy from Norwegian company FXI Technologies is "a USB stick sized computer that provides a single, secure point of access to a user's personal cloud services and apps through their favorite operating system, while delivering a consistent experience on any screen."

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One of a range of single-board computers from Hardkernel, the Odroid-CI is another $35 competitor for the Raspberry Pi. It has a similar hardware specification to the Pi, with a 1.5GHz quad-core Amlogic Cortex-A5 (ARMv7) CPU and 1GB of RAM. Available operating systems include Ubuntu 14.04 or Android KitKat.