If you were going to write some HTML using the Mac’s free text editor TextEdit you need to make sure the Preferences are set for plain text, not for RTF. [See My first page – a basic HTML recipe.]
I suggest the following choices for the Preferences. The screenshots below are from Mac OS X 10.5.4 (Leopard). If you use a different version of the Operating System some things may be different.
The important choices under New Document are the Plain Text format and not to check the Smart Quotes option. Wrap to page is a good choice to stop long lines of text from dribbling off to the right so you have to scroll sideways. Window Size and Font are purely a matter of taste — set them how you like.
For the Open and Save preferences check the box for Ignore rich text commands in HTML files. If you follow the brief ‘recipe’ in my next post choose one of the XHTML types for HTML Saving Options, rather than one of the HTML (no X) types.
Update: The whole series: