We’ve already waxed and waned about the little Raspberry Pi computer, so we won’t go over old ground. We love the concept behind the educational trust that drives this product, and we hope that it really does fulfill its promise as a solid introduction to computing for all-comers. But one of the major things this tiny device has done is encourage a whole ecosystem of rivals, all trying to deliver ultra low cost, small footprint processing on demand. We thought we’d take a look at a few.

The Carambola is a open source Linux based module which comes with 8 MB of Flash memory and 32GB of RAM. It features a 2.4GHz processor, high speed WiFi on board, ultra low power and a starting price of just Euro 22.00 per unit.

The specification and price make this a very interesting alternative to the RaspPi. [Update: Oops, my bad. This is a radio module, not a computer board. Mea Culpa Ignarus. Sorry folks.]

The Cubieboard features a lower specification much closer to the Pi with an ARM A8 processor, 512MB of RAM, Ethernet but no WiFi, 4GB of NAND Flash memory and a microSD slot. The price is rumored to be around $49.00, although first shipments are already sold out.

The device will support the Android operating system out of the box, as well as Linux and other systems.

The Alpen Dual Core Android Thumb PC is a much more complete system in a box than the previous two products, and crucially it’s the first of the dual core Android powered products of this size to hit the shelves. It comes with a 1.5 GHz processor, 1GB of RAM, 4GB of NAND Flash memory and support for up to 32GB in additional microSD card storage.

This is not such a low cost product, however, at $108, although it does come with WiFi, 1080p very high resolution graphics and a built in 3D graphics accelerator for games.

The A13-OLinuXino WiFi DEV has a 1GHz processor, but only 512MB of RAM. It does however come with HDMI out for connecting to a TV, and there’s WiFi on board as well as USB power socket and a microphone input socket.

The device features an impressive array of expansion capabilities though, including support for the popular Zigbee tech. The price is Euro 55.00.

The Hackberry A10 is an Australian product which squeezes a 1.2GHz ARM A10 processor, 1GB of RAM, 4GB NAND Flash memory and an SDHC slot for up to 32GB storage onto an impressively small footprint board.

It runs on Android or Linux, comes with WiFi and Ethernet on board and can output 1080p video resolution through the HDMI port. The board retails at $65.00 but again is out of stock, proving its popularity.

Not to be outpaced by developments around the world, the veteran BeagleBoard developers have released the BeagleBone, a Linux based computer running with an ARM A8 processor and featuring a 2GB microSD card containing the Angstrom Linux operating system and tools.

No WiFi, just Ethernet on board, this is very much a bare bones computer (hence the name, eh?) which will set you back $89.00.

Last but not least, a slightly different beast, the Open Exynos4 Quad board is a quad core ARM A9 computer which features a 1.4GHz processor, 1GB of RAM, 1080p HDMI out, Ethernet on board and six USB ports.

It’s designed as a smartphone development device, and so runs with Android 4.0.4 ICS, and supports external add-on modules for WiFi and cameras. Priced at $129.00 per unit.