The app Quiver is available on the Mac app store today for $2 as part of “$2 Tuesday”.
Think of it as a cross between Evernote, Code Snippet tool, and MarkDown editor.
It doesn’t have support for any BASIC type languages yet, but I guess if the author gets asked he’ll include support for Xojo too.
I know $1.99 is not a lot. But there is also a free trial for download at http://happenapps.com/#quiver
From the reviews on the MAS, though, it looks as fantastic product.
Incidentally, the two dollars tuesday looks like an interesting venue to promote apps on the MAS : http://twodollartues.com/developers/
Thank you for the tip, Markus. Following my purchase I heard back (email) from the developer of Quiver; they will be adding XOJO code syntax support.
I asked them and send them the link to the keywords page 
And yup, just checked, got the email too 