Hey there... As a Mac developer myself, I know that it does depend on your text editor. If you are editing any server scripts you need to use a safe text editor or script editor.
For my Perl scripts, SQL, Java and so on - Adobe GoLive will open any of these and allow for safe editing - without the added zeros and such that your speaking about.
These also are great:
MS Word
Mac Perl [macperl.org...]
Mac Simple Text by the way is not the best editor on earlier OS 9. But Simple Text for OS X is a good bet.. just make sure to set to plain text and not rich text (RTF) as you know Mac OS X is Unix base (grin) so your scripts should be easier to edit there.
Enjoy and hope this was a help.
~GoV