I missed the mail notification for the replies, sorry guys!
Yes, we are using bitmap fonts, created this way:
global.SomeFont = font_add_sprite_ext(some font sprite, char list, true, 1);
After that, using fonts goes totally straightforward with
draw_text or
draw_text_ext. The only problem with HTML5 is that it doesn't automatically wrap, otherwise everything is fine. Actually, I solved by writing my own text box with a decent auto wrap, honestly I believe it may work fine for the rest of the project...
EDIT: I feel I should note that a major overhaul of HTML5 has been done and a (near) future update should resolve most of the issues people are having... I know that doesn't help you now but at least you know that the target has been getting some love and should be up-to-spec soon.
This is good news, thanks for sharing. I was about to open another HTML5 thread about fullscreen not getting input correctly...
I believe we will have to work on this HTML5 game for quite some time, so I'm glad to hear this.