ASM coding, do you use a special program, or can you use C for asm-coding instead

If you code in ASM, do you use a program for it?
Is there any development tool regarding ASM (a real development tool, not some stupid editor recognicing ASM-syntax),

eg. If you program in C++ you might have Visual studio C++

And how do you debug your coding errors in ASM?, isnt it hard to make correct codes in ASM, if you make semantic errors, it gotta be hard to trace the problem. I have seen some keygen source code in ASM, but it doesn't look easy to edit.

Is it possible to just program in C, and insert the asm code as a func of

__asm()
link for info about this func here:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccelng/htm/msmod_35.asp


I belive ppl code keygen in ASM to repeat the assemble-code they analysed from the program key-routine to make a valid key. But is it possible to do this if I just stick to plain C/C++ programming using the mentiened func above?



- Existens of develment tool for ASM-coding?
- Possible to just use __asm func and stick with coding in C?