A few fans have put up a load of Glorantha products and information up at RPGGeek.com. Check it out! And if you really want to help us out (and the volunteers) become fans of individual products and click that you “Like” various images.
Check it out here:
The background of Glorantha is split into three Ages (First, Second and Third). The Third Age is the primary setting for published material, although there was a Second Age setting book.