eZX80Sparky and eZXBASIC are current projects directly related to each other.  Combined they make a modern 8 bit computer using modern components.  Unlike most 8 bit projects today, this is not a reproduction of a vintage machine.  This is a whole new beast all together.

eZ80Sparky is a hardware project based upon the ZiLOG eZ80 CPU, which is a much more advanced version of the once popular Z80 CPU of MSX and CP/M fame.  The eZ80 incorporates a linear 24 address space, instead of the Z80's 16 bit address space.  The eZ80 is a superscalar design with pre-fetch, which makes the eZ80 four times faster than a Z80 at the same clock speed.  The eZ80 is available in speeds up to 50MHz, much faster than 8 bit CPU's 20 years ago!  A 50MHz eZ80 runs about as fast as a 200MHz Z80 (if one existed).

The operating system, called "eZXBASIC" is a superset of the classic Sinclair ZX Spectrum operating system.  Before all of you ZX fans get all excited, this is not even remotely compatible with that machine any more.  It has grown way beyond it's 16K roots.  eZXBASIC has grown to nearly 72K and should peak at 128K when completed.  It's OS is merely based upon the Spectrum's OS design that's all.  The eZ80 is capable of running in Z80 mode and thus could "emulate" a Spectrum somewhat, but the timing of the eZ80 would not make it cycle compatible no matter what you do.