AVR Studio and WinAVR as C teaching tools...

AVR Studio when run in combination with WinAVR (packaging avr gcc, avr-libc and all the other gubbins) provides an awesome 1st learning environment for people learning C for the first time

• Completely free, for students and staff
  
• Traffic light graphical message highlights: Green spots next to messages when things went right, yellow for warnings and red for errors. Instantly understandable!
• Graphical indication of the current location in the program with autostep to move step by step through the program - outlines the flow immediately.
• Processor window showing the program counter, cycle counter (how much time has your program taken?). Turning ints to floats added 4000 cycles to a simple test program.
• Internal processor registers very visible
• I/O View graphically highlights ports and pins with a row of 8 squares which are filled when the bit is set. Instant graphical Hex to Binary

I really think that this is an ideal learning environment, not too big and not too small.