From Hamsterworks Wiki!
The Zedboard is my first FPGA development board with a 'true' CPU on it.
Unlike what you might expect, the Zynq-7020 device is actually has two distinct domains on it - the ARM-based Processor System (PS) and the Programmable Logic (PL). They are connected using an AXI3 bus endpoint. Conceptually it is much the same as having an FPGA on a PCIe card in your PC, but all in one tiny chip package.
So far I've ported my Mandelbrot Fractal viewer over to the programmable logic, and booted Xillinux (Ubuntu for the ZedBoard) on it too.
The logic is about 50% faster than my Spartan 6 LX9 Papilio Plus, but there is about ten times as much of it too!
When running Linux you would think that it is much like a Raspberry Pi, but it is so much more. The DDR3 memory is much faster, the dual-core 1.3GHz CPUs is much faster too, the LAN is Gigabit, and the graphics is far more snappier.
I like to think of it as the Raspberry Pi for professionals.