AppleFPGA is a System on a Chip (SOC) based on an unenhanced Apple ][e using the Digilent Spartan 3 Starter board. The Spartan 3 Starter board includes a Xilinx Spartan 3 XCS3s200 FPGA and 1 Meg of static RAM (SRAM). See the Digilent web site for more details of the Starter board. There is no 6502 processor or other peripherals. All functions are derived using the Hardware Description Language (HDL) Verilog.
The Apple1 is a questionable target for a C compiler due to its small memory size and disjointed memory map. The Replica1, on the other hand, is a near perfect single board target with its 32K contiguous RAM and nice I/O expansion. Compare this with what WDC offers as a single board development platform for $695.