As already noted, DON'T SHOUT! (writing in all uppercase is considered SHOUTING and, therefore, rude).

For a list of 8051 compilers, click the 'Links' button.

Note that a compiler is not used for writing code:
You use an editor to write the code; once you have written it, you pass it to the compiler which translates it into Object code.

'C' source files are just plain text files - so you can use any editor you like (or even one you dislike) to write your code.
You could even use a wordprocessor, provided it can save unformatted, plain ASCII text files...