MyBB Community Forums

I want a real clean/seo URLs plugin, something like wordpress or vBulletin offers. I would be willing to pay for this plugin...

IDEALLY I'd like

mysite.com/forum/music/
mysite.com/forum/thread/new-album-coming-this-summer/

Not possible with a plugin. frostschutz's Google SEO gets the best out what a plugin can do. For more SEO URLs you have to modifiy MyBB's core (the deeper core with a lot of files...).

Why is it not possible?

No one said it's not possible, it's just not possible with a plugin. You'd need to edit numerous core files.