My own Modifications
 

I'm currently in an argument with a co-worker of mine about a rule with vBulletin. Am I allow to build my own modification(s) on a "published" site?

For instance: Can I make a moderator app?


He says I have to purchase a 900 dollar "developer" license in order to make my own plugin on MY site.



He's wanting to go half with me in buying a the software for the site we also own together, however he has some issues since he read a rule in the licenses agreement about not being able to make your own mods on a publish site.