Subject Mozilla Firebird for Mac OS X is still released as Firebird
Author eric_ck_leung
According to the article:

Nightly Builds of Mozilla Firebird Available for Mac OS X
dated May 4th, 2003.
with product link:

The newly released Mozilla Browser/Mozilla Firebird is still released
as product name = 'Firebird'
It seems that it does not follow the earlier 'Mozilla Branding' Guideline!