J51 a Java Intel MCS51(8051,8052, etc) family microprocessor emulator, with integrated disassembler, debugger, Intel hex file loader and more. Standard peripheral emulated Timer 0/1 (Mode 0,1,2 and interrupt), Serial interface (Only in polled mode) ,Standard port 0 to 4. Microprocessor Intel MCS 8051 (no peripheral),Intel 8051,Intel 8052,Philips LPC674,Philips LPC900.

Atanua is a real-time logic simulator designed for educational use. It has an intuitive, OpenGL accelerated user interface, with which the user can place components and wires. Components include all common logic blocks, including gates, latches and flipflops, about 30 different 74-series chips, an 8051 microcontroller variant, various LEDs, buttons and 7-seg displays.