Right now a fully functional NMOS 6502 (with non BCD variants).
Also a fully emulated PIA 6532 RIOT chip.
TIA emulation is in progress to eventually create an atari 2600 emulator for both playing games and being used as a platform for machine learning.
Also some misc utilities developed along the way (disassembler, c64 basic, quick and dirty hand assembler helper).
Random semi-coherent thoughts on this development at https://maker-rambling.blogspot.com/