Help? I want to make a bridge

[danrulz98]

I have a few applications on my website and it would be really nice if there were bridges available. I want to make (or try anyway) a few but I don't know where to start.
The things I want to bridge are
WB
MyBB
Ajax IM
and MediaWiki

I know there is a bridge between MyBB and MediaWiki but I don't know if there is anything to go between the other scripts.
Everything is running from the same database and there are only a few users on MyBB and Ajax IM that wouldn't mind re-making their accounts.

Anyway, where would I even begin?

[iceat]

you should begin by writing down what you would like to achieve. Why do you want that bridge? What possibilities would you like to create with your bridge? ...

[danrulz98]

1. I want users to be able to have one login site wide while only having to register once.
2. Simultaneous logon (I think this can be done with cookies)

I'm thinking, it would be nice if I could make a script that would either inset the needed values into each table for each script or make all of the scripts use one table for the users. each script would have to use the same hash for encrypting the password. It would also be nice if one re-capacha image worked for all at once.
I'm thinking the user will probably get 4 activation emails but that is fine. Something else I could do is make a script that uses the registration script for each script.